The RTT SmartConnect App provides the ability to remotely view oven status when the control panel is connected to an active internet connection. SmartConnect provides the ability to monitor temperature, process time remaining, elapsed time, system faults or burner status remotely.
Air Make-up Unit Technical Training Bryan Willis – Controls Manager
• Section 1 – The Basics • Section 2 – Component Identification • Section 3 – Interlocks • Section 4 – Initial Start-up • Section 5 – Booth Balancing • Section 6 – Booth/AMU Operation • Section 7 – Troubleshooting
Section 1
The Basics
• •
Understand the acronyms.
Purpose of an Air Make-up Unit.
• Basic understanding of what it means to balance a booth. • What is an NTRL? • Basic voltage, amperage and pressure readings required for setup and troubleshooting.
Section 1
• Acronyms
• AMU – Air Make-up Unit • Introduces filtered/tempered air into a booth, room, or building. • CFM – Cubic Feet per Minute • Volume of air a fan is moving. • FPM – Feet Per Minute • Speed at which air is moving though a booth or duct. • “w.c. – Inches of Water Column • Pressure value lower than 1P.S.I.. There are approximately 28”w.c. in 1 P.S.I. • VFD – Variable Frequency Drive • Used to vary the speed of a motor connected to a fan and therefore the CFM the fan produces. • FLA – Full Load Amps • The maximum amps at which a motor can safely operate. • NRTL – Nationally Recognized Testing Laboratory • Recognized by governing officials as a 3 rd party group that confirms products meet or exceed various design standards • NFPA – National Fire Protection Association • Organization that has developed design standards devoted to eliminating death, injury, property and economic loss due to fire, electrical, and related hazards.
Section 1
Purpose of an Air Make-up Unit (AMU) An AMU is used to replace a volume of air that has been removed by an exhaust fan or fans
The AMU pulls air from the outside of the building where it is then ducted into a booth or spray area. Because the air is pulled from outside, the air will need to be heated during the winter months. More advanced AMUs can also cool the air, and control the humidity.
The CT Series AMUs use a Midco or Eclipse direct fired burner to accomplish the heating process.
Section 1
Balancing a Booth In order to balance a booth, the amount of air entering the booth must be equal to the amount of air exiting the booth.
If too much air is entering the booth from the AMU, then the booth will run positive and the doors will blow open.
If too much air is exiting the booth from the exhaust fan, then the booth will run negative and potentially pull in debris from unfiltered opening.
Section 1
Balancing The CT and CTC units include an auto-balance function that will maintain the desired booth pressure automatically. The desired pressure is set using the Carel controller. This controller displays the current booth pressure.
Current Booth Pressure • Positive value means that more air is coming into the booth than going out. • Negative value means that more air is leaving the booth than going in.
Section 1
Balancing Balancing is accomplished using a Variable Frequency Drive (VFD) on the supply fan (AMU) and the exhaust fan. Using the VFDs allows the fans to turn at variable speed which translates to variable Cubic Feet per Minute (CFM). • Booths are designed to operate with a specific Feet Per Minute (FPM) in mind. • The FPM will vary by booth type.
• During commissioning, the AMU fan speed is set to achieve the desired FPM through the booth. • The AMU fan speed should not change during spray mode, so the same volume of air is continuously being introduced into the booth. • The exhaust fan speed will need to change during normal operation.
Section 1
• Exhaust fans need to run at whatever speed is required to match the CFM being introduced by the AMU (assuming the operator has set the controller for 0.000”w.c. balanced pressure) • When exhaust filters are new/clean, there is less restriction on the exhaust fan, therefore it doesn’t have to run at full speed to maintain the booth pressure. • As exhaust filters load, there is more restriction on the exhaust fan, therefore it needs to speed up to maintain booth pressure. • Pressure across the exhaust filters should be monitored so that as the filters reach their maximum loading, the operator knows to replace them. This pressure is monitored on the booth manometer. • If the filters are not changed, eventually the exhaust fan will be running at full capacity but the booth will no longer balance because there is too much restriction on the exhaust fan.
Section 1
Most common AMU series offered by RTT
• CT Unit
• No cure cycle. • Fan and a burner, the burner can be turned on or off. • Normally includes a VFD for exhaust fan. • When VFD is included, auto-balance is standard. • Booth lighting controls included. • CTC Unit • Includes cure cycle. • Fan and a burner, the burner can be turned on or off. • VFD for exhaust fan included with auto-balance functionality. • Booth lighting controls included.
Section 1
What is an NRTL? • Underwriters Laboratories (UL), Intertek (ETL), and Eurofins (MET) are examples of NRTLs. • 3 rd party organizations that test products to confirm they meet the required design standards. • Standards commonly used by RTT include:
• NFPA33 • NFPA70 • NFPA86
• ANSI Z83.4 • ANSI Z83.18 • UL 508a
Section 1
• Volts • When compared to water in a pipe – volts is similar to pressure • Electricity does not need to be flowing to have voltage • When a voltmeter is connected to a live circuit, it will read the voltage even if there is no active load (motor or lights) • Similar to a pressure gauge on a pipe
• Why understand volts is important during start-up and troubleshooting • Proper voltage is required for the unit to operate • Voltage that is too high or too low will cause damage or failure to components • Different types of voltages are used depending on the devices being operated
Section 1
• VAC = Volts AC (Alternating Current) • Alternating Current voltage is used to transmit power long distances
• Power from building into the unit is VAC • Control power and lighting power is VAC
• VDC = Volts DC (Direct Current) • Direct Current is used for low voltage control devices • PLCs, Actuators, Displays, etc. • DC voltage can fluctuate between 0 and 24 depending on signal type • Phase • Only applies to VAC • Single phase or three phase • Single phase power is normally used in homes and small businesses • Three phase power is normally used in large commercial and industrial sites
Section 1
Typical voltages used in commercial and industrial job sites: 208 volt 1 phase 230 volt 1 phase 208 volt 3 phase 230 volt 3 phase 460 volt 3 phase
• Voltage may vary +/- 20 volts
Section 1
To test AC voltage: Select the V~ ~ Stands for AC
Section 1
• Amps • When compared to water in a pipe – amps is similar to flow (gallons per minute) • When water is flowing through a pipe, the pipe creates resistance to its flow. There will be pressure drop from one end of the pipe to the other. • Smaller/longer pipe will cause larger pressure drop from one end to the other. • The same applies to electricity in the form of wire. • Smaller/longer wire will cause a larger voltage drop from one end to the other. • Why understand amps is important during start-up and troubleshooting • Amps determine how hard a motor is working • A motor has a maximum amperage based on its HP rating • If a motor is drawing too many amps, it will overheat and eventually fail
Section 1
To test AC amperage: Select the A~ ~ Stands for AC Run only 1 wire through the amp clamp. For three phase power, measure each leg and then average the three. If one leg is much higher or lower, that may indicate a problem.
Section 1
• Inches of water column – example: 7”w.c. • Pressure that is lower than 1 P.S.I. • Approximately 28”w.c. in 1 P.S.I. • Commonly used fuel pressures • 7”w.c. – homes and light commercial/industrial facilities • 14”w.c. – commercial/industrial facilities • 56”w.c. – default pressure CT and CTC AMUs are designed to operate at • 140”w.c. – industrial facilities
• Other pressures to note • Booth pressure – Range: - .025”w.c. to +.025”w.c. Usually set around zero • Burner profile pressure – Range: .5”w.c. to .7”w.c. Optimal pressure is .6”w.c. • Burner manifold pressure – Fuel pressure downstream of the valve train going into the burner.
Section 2
Component Identification
•
Location of AMU and Remote
• Location of dampers, temperature sensors, and access doors • Location and function of controls components • Location and function of valve train components • Location and function of fan and burner
Section 2
CT = “Heat Only” CTC = “Heat & Cure”
AMU:
Main power drop from building Control panel contains all power distribution, VFDs, PLC, Relays, Flame Controls, Etc.
All interlocks wire to this control panel. Exhaust fans wire to this control panel. Light fixtures wire to this control panel. Field wiring to remote control panel.
Remote Panel:
No power circuits in this panel, only low voltage control wiring. Pressure transducer installed in this panel will need1/8” tubing ran to booth wall. Remote PLC display installed on the door of this panel.
Section 2
Discharge Damper (Outdoor Units) Closed when the unit is not running, open when the fans are on.
Discharge Temperature sensor . Monitors the air temperature leaving the AMU
Access Door Allows access to AMU fan, motor, belts, high temp limit, burner, profile damper, etc.
Schematics and Unit Information Component list, schematics, manufacturing plate, warnings, etc.
Section 2
Incoming Gas Pressure Test Port ¼” threaded cap
Pilot Gas Solenoid Turns gas on/off to the pilot
High Gas Pressure Switch Monitors fuel pressure entering the burner.
Pilot Gas Regulator Reduces incoming gas pressure for proper pilot size
Main Gas Inlet 2 lbs (56”w.c.) Typical fuel pressure
Burner Manifold Pressure Test Port ¼” threaded cap
Gas Actuator Controls gas flow to burner.
Primary Gas Valves Turns gas on/off
Main Gas Regulator Controls gas pressure to burner during main flame.
Section 2 Main Disconnect Incoming Power Lands Here
Control Transformer Lowers incoming voltage to 120vac
Relays Various switching of control circuits.
Power Distribution Splits the main power into branches
Transformer Provides 24vac to various components. Terminal Block Field wiring connections land here. PLC Controls fan on/off, burner on/off, and cure logic.
Fuses/Branch Circuit Protection Protection for the power circuit devices (VFDs, Control Transformer, Lights, Etc.)
Exhaust Fan VFD Controls speed of exhaust fan(s)
High Temp Limit . Shuts off the burner if the temperature is too high. On cure models, this is digital. Flame Controller . Monitors flame condition and controls gas blocking valves/pilot.
AMU Fan VFD Controls speed of AMU fan
Exhaust Fan Motors Fuses Protection for exhaust fan wiring.
Service Switches . Allows technician to turn on/off fan and burner
Exhaust Fan Motors Overloads Protection for exhaust fan motors.
Air Pressure Switches . Prevents combustion if air pressure across the burner is too low or too high.
Booth Lights Contactor Relay to turn booth lights on/off.
Section 2
Forward Curve Fans • Standard for CT and CTC gas fired units • Low to medium static pressures (3”w.c. TSP) • Quiet operation
Rotation
High Temperature Limit
Figure 1: Forward Curve Centrifugal Fan Wheel
Rotation Indication
Motor
Fan Housing
Belt & Drive
Section 2
Direct Fired Burner
All products of combustion are introduced into the air stream.
Section 2
Air Baffles
•
600,000 BTU per linear foot
• 110 ° F Temperature Rise (Natural Gas) • 90 ° F Temperature Rise (Propane Gas)
Burner Casting
Pilot Assembly
MIDCO HMA-2 Direct Fired Burner
Section 2
Burner Casting
• 750,000 BTU per linear foot natural gas • 630,000 BTU per linear foot propane gas • 120 ° F Temperature Rise • Fuel specific burner due to port size in manifold
Air Baffle
Pilot Assembly
ECLIPSE AH-MA Direct Fired Burner
Section 2
Gas Orifices
•
MIDCO HMA – Cast iron burner • Natural Gas = #31 • Propane Gas = #45
• MIDCO HMA2 – Aluminum Burner • Natural Gas or Propane Gas = #31
•
Eclipse/Honeywell AHMA • Natural Gas = 2.4mm • Propane Gas = 2.0
Section 2
Midco Pilot Assembly
Pilot is on during initial burner ignition only.
Flame Rod
Flame Rod Flame Detection
Ignition (Spark) Rod
Pilot Gas Line Connection
Ignition (spark) rod
Section 2
Eclipse/Honeywell Pilot Assembly
Pilot is on during initial burner ignition only.
Section 2
Midco Burner Assembly Inside the AMU
Pilot Gas Line Connects to solenoid inside control panel.
Burner Various lengths based on BUT requirements of the unit.
Flame Rod Detects presence of a flame within the burner. Connects to
Profile Damper Open during spray mode Closed during cure mode
Fire Eye flame controller in the control panel
Section 3
Interlocks
• • •
What is an interlock?
Types of interlocks used by RTT
Detailed functionality of each type of interlock
Section 3
What is an interlock? (Two Types) “Process Interlock”
A device required to ensure proper equipment start up, operation and shutdown. “Safety Interlock” A device required to prevent property damage and to prevent operator injury or death.
Section 3
Typical interlocks found on RTT series AMUs
Air Solenoid Valve
• • • • • • •
Door Limit Switch
Contactor
Light Lens Limit Switch
Air Pressure Switch
Gas Pressure Switch
Temperature Limit
Section 3
Why do we use interlocks? To conform with various standards in our
industry:
NFPA33 – Standard for Spray Application Using Flammable or
Combustible Materials
NFPA86 – Standard for Ovens and Furnaces
ANSI Z83.4 – Non-recirculating direct gas-fired industrial air
heaters
UL844 – Standard for Luminaires for use in Hazardous (Classified)
Locations
Section 3
Per NFPA33 14.3.5.2 – Spray equipment
cannot be operated unless the exhaust
ventilation system is operating and
functioning properly and spray application is
automatically stopped if the exhaust
ventilation system fails.
Section 3
Air Solenoid Valve
When 120vac signal from control panel is not present, the air solenoid valve is off (closed). No air is allowed to pass which means the operator cannot use the spray gun.
Compressed Air from compressor
(ACC-5080)
Air Solenoid Valve Electrical Symbol
Section 3
Air Solenoid Valve
When 120vac signal from control panel is present, the air solenoid valve is on (open). Air is allowed to pass which means the operator can use the spray gun.
Compressed Air from compressor
(ACC-5080)
Air Solenoid Valve Electrical Symbol
Section 3
Per NFPA33 13.3.1.3.2 – Where industrial
air heaters are used to elevate the air
temperature for drying, curing, or fusing
operations, means shall be provided to
deter entry into the spray booth or spray
room during the drying, curing, or fusing
operation and interlocks shall be provided
to shut down the drying, curing, or fusing
operation if entry is made.
Section 3
Door Limit Switch
120VAC signal is sent to the door limit switch. If the door is open, the 120VAC signal is not allowed to leave the switch.
Spring loaded lever.
Striker plate.
Booth door open.
Door Limit Switch Electrical Symbol
(EXP-LMT-SWITCH)
Section 3
Door Limit Switch
120VAC signal is sent to the door limit switch. If the door is closed, the 120VAC signal is allowed to leave the switch.
120VAC signal back to control panel or other device.
Spring loaded lever.
Striker plate.
Booth door closed.
Door Limit Switch Electrical Symbol
(EXP-LMT-SWITCH)
Section 3
Contactor
A motor contactor is the device that is used to switch on/off the 3 phase high current power to a motor. 120VAC signal is sent to the motor contactor auxiliary contact. If the contactor is off, the 120VAC signal is not allowed to leave the contactor.
Contactor Electrical Symbol
3 phase motor connection.
Section 3
Contactor
Signal from toggle switch or PLC
When a signal from the toggle switch, or PLC is sent to the coil of the contactor, it creates a magnetic field that causes the contactor to “pull in” which then sends 3 phase power to the motor, and 120vac signal out to various devices.
120VAC signal out to air solenoid or other devices.
Contactor Electrical Symbol
3 phase motor connection.
Section 3
Contactor When a signal from the toggle switch, or PLC is sent to the coil of the contactor, it creates a magnetic field that causes the contactor to “pull in” which then sends 3 phase power to the motor, and 120vac signal out to various devices.
Signal from toggle switch or PLC
The signal can also be wired to a standard 120 volt outlet to be used by an airless spray gun
3 phase motor connection.
Section 3
Light Lens Limit Switch
120VAC signal is sent to the light limit switch. If the glass is removed, the 120VAC signal is not allowed to leave the switch.
Air Gap.
Magnet attached to glass lens.
Light limit switch. (AKA: Reed Switch)
Light Lens Limit Switch Electrical Symbol
Section 3
Light Lens Limit Switch
120VAC signal is sent to the light limit switch. If the glass is installed, the 120VAC signal is allowed to leave the switch.
120VAC signal to next light fixture or other device, or back to control panel.
Magnet attached to glass lens.
Light limit switch. (AKA: Reed Switch)
Light Lens Limit Switch Electrical Symbol
Section 3
Per NFPA86 8.6.1 – Where a fan is
essential for purge or safety ventilation of
an oven or allied equipment, fan operation
shall be proved and interlocked into the
burner management system.
Section 3
Air Pressure Switch
Adjustable Pressure Dial
Air pressure switches can be used in a variety of configurations and applications.
Electrical Contact (Normally Closed)
Normally Open Normally Closed Hose Barb Fittings Threaded Fittings
Electrical Contact (Common) Electrical Contact (Normally Open)
Adjustable from .16” w.c. to 1.2” w.c. Adjustable from .4” w.c. to 4” w.c.
Electrical Entrance
Minus Pressure Port
Air Pressure Switch Electrical Symbol
Plus Pressure Port
Section 3
Air Pressure Switch Proving a Fan
Discharge of fan (Plus side of switch)
A pressure switch installed across the inlet and outlet of a fan can prove when the fan is moving air.
Minus tube
Plus tube
Air Pressure Switch
Air Pressure Switch Electrical Symbol
Inlet of fan (Minus side of switch)
Section 3
Air Pressure Switch Proving a Fan
Discharge of fan (Plus side of switch)
120VAC signal is sent to the air pressure switch. If the fan is off, the 120VAC signal is not allowed to leave the switch.
Minus tube
Plus tube
Air Pressure Switch
Air Pressure Switch Electrical Symbol
Inlet of fan (Minus side of switch)
Section 3
Air Pressure Switch Proving a Fan
Discharge of fan (Plus side of switch)
120VAC signal is sent to the air pressure switch. If the fan is not generating the correct amount of pressure, the 120VAC signal is not allowed to leave the switch. When the fan energizes, and the proper amount of air pressure is detected, 120VAC signal is allowed to leave the switch back to the control panel or other device.
Minus tube
Plus tube
Air Pressure Switch
Air Pressure Switch Electrical Symbol
Inlet of fan (Minus side of switch)
Section 3
Per NFPA86 8.9.1 – A low fuel pressure switch
or sensor shall be provided and shall be
interlocked into the burner management system.
Per NFPA86 8.9.2 – A high fuel pressure switch
or sensor shall be provided and shall meet the
following criteria:
(1)It shall be interlocked into the burner
management system.
(2)It shall be located downstream of the final
pressure-reducing regulator.
Section 3
Gas Pressure Switch
Gas pressure switches are used with a safety controller and can be configured for normally open or normally closed use. Typically the gas pressure switches have an adjustable pressure range.
Oven Valve Train
High Gas Pressure Switch
Low Gas Pressure Switch
High Gas Pressure Switch Electrical Symbol
Low Gas Pressure Switch Electrical Symbol
Section 3
Gas Pressure Switch
NFPA 86 requires that an oven operate within a specified gas pressure range (not too high and not too low). The high gas pressure switch ensures the pressure is not too high. The low gas pressure switch ensures the pressure is not too low.
Oven Valve Train
High Gas Pressure Switch
Low Gas Pressure Switch
High Gas Pressure Switch Electrical Symbol
Low Gas Pressure Switch Electrical Symbol
Section 3
Gas Pressure Switch
120VAC signal is sent to high gas pressure switch.
Oven Valve Train
High Gas Pressure Switch
Low Gas Pressure Switch
High Gas Pressure Switch Electrical Symbol
Low Gas Pressure Switch Electrical Symbol
Section 3
Gas Pressure Switch
120VAC signal is sent to high gas pressure switch.
If gas pressure is not too high, 120VAC signal is allowed to pass to the next device.
Oven Valve Train
High Gas Pressure Switch
Low Gas Pressure Switch
High Gas Pressure Switch Electrical Symbol
Low Gas Pressure Switch Electrical Symbol
Section 3
Gas Pressure Switch
120VAC signal is sent to high gas pressure switch.
If gas pressure is not too high, 120VAC signal is allowed to pass to the next device. If gas pressure is not too low, 120VAC signal is allowed to return to the control panel.
Oven Valve Train
High Gas Pressure Switch
Low Gas Pressure Switch
High Gas Pressure Switch Electrical Symbol
Low Gas Pressure Switch Electrical Symbol
Section 3
Gas Pressure Switch
If at any time the pressure falls out of range, the appropriate switch will open or close and require a manual reset by the operator. The manual reset is an NFPA86 requirement to ensure the operator knows that there was a gas pressure fault.
Oven Valve Train
High Gas Pressure Switch
Low Gas Pressure Switch
High Gas Pressure Switch Electrical Symbol
Low Gas Pressure Switch Electrical Symbol
Section 3
Gas Pressure Switch
Gas pressure switches are part of a Safety Interlock. To accomplish Safety Interlock status, the switches must be wired to a Listed Safety Controller.
Listed Flame Safety Controller
Section 3
Per NFPA33 13.3.1.2 – For fully enclosed
spray booths and spray rooms, a high
temperature limit switch shall be provided
to automatically shut off the drying
apparatus if the air temperature in the
spray area exceeds 93C (200F).
Section 3
Temperature Limit
Temperature Limit Controller
The digital FM approved temperature limit allows for precise adjustable temperature limits to be programmed for various functions. The controller connects to a temperature sensor that is mounted in the booth or ductwork.
Temperature Sensor Mounted In Ductwork
Section 3
Temperature Limit
Temperature Limit Controller
120VAC signal is sent to the temperature limit.
If the temperature detected by the temp sensor is below the set point in the controller, 120VAC is allowed to pass through the controller.
Temperature Sensor Mounted In Ductwork
Section 3
Temperature Limit
Temperature Limit Controller
120VAC signal is sent to the temperature limit.
If the temperature detected by the temp sensor is above the set point in the controller, 120VAC is not allowed to pass through the controller. This creates a fault and causes the burner to shut down.
Temperature Sensor Mounted In Ductwork
Section 3
Temperature Limit
The temperature limit is part of a Safety Interlock. To accomplish Safety Interlock status, the limit must be wired to a Listed Safety Controller.
Listed Flame Safety Controller
Section 3
Common Interlock Example
Operator is allowed to spray only when the fan is running.
Fan proven signal
Compressed Air
Section 3
Common Interlock Example
Operator is allowed to spray only when the fan is running, and the booth doors are closed.
Fan proven signal
Fan proven andbooth door closed Signal
Compressed Air
Section 3 Common Interlock Example
Operator is allowed to spray only when the fan is running, the booth doors are closed, and the light fixture lens is installed.
Fan proven signal
Fan proven andbooth door closed and light fixture lens installed Signal
Fan proven andbooth door closed Signal
Compressed Air
Section 3 Common Interlock Example
Operator is allowed to spray only when the fan is running, the booth doors are closed, the light fixture lens is installed and the filters are OK.
Fan proven andbooth door closed and light fixture lens installed and filters OK Signal
Fan proven signal
Fan proven andbooth door closed and light fixture lens installed Signal
Fan proven andbooth door closed Signal
Compressed Air
Section 4
Initial Start-Up
• • •
Tools Required Items to inspect
Initial readings to gather
Section 4
Required Tools
• Basic hand tools including but not limited to: screwdrivers, wrenches, plyers, pipe wrench, wire strippers, technicians screw drivers, hex wrench set, drill and bits/drivers, electrical tape, Teflon tape, wire nuts, 1/8” hose barbs, ¼” hose barbs, etc. • Voltmeter • True RMS Ammeter • 0” to 10” Manometer Gauge (Ex: Dwyer 477AV -0) • 0” to 200” Manometer Gauge (Ex: Dwyer 477AV -3) • Printed copy of start-up guide, schematics, and O&M
Section 4
Initial Items to Inspect
•
Filters are correctly installed in the intake of the AMU
Filters are directional
Section 4
Initial Items to Inspect
• Filters are correctly installed in the in intake of the booth (green/blue side of the filter is sticky and should be on the downstream side of the air flow)
Section 4
Initial Items to Inspect
• Filters are correctly installed in the exhaust plenum of the booth.
Filters installed that were not in the original design
Factory RP style filters installed
Section 4
Initial Items to Inspect
•
Fuel line has been purged of air
Section 4
Initial Items to Inspect
•
Exhaust motors are wired for proper voltage • Take photo of the MFG tag on the motor for future reference of FLA rating
Section 4
Initial Items to Inspect
•
AMU motor is wired for proper voltage • Take photo of the MFG tag on the motor for future reference of FLA rating
Section 4
Initial Items to Inspect
• Ensure fire suppression is not active and if any sprinkler heads are used, they have an adequate temperature rating. • Orange, Red or Yellow heads might mean the rating is too low • If unsure, consult with fire suppression company before igniting burner • High temperature limit set point of AMU is typically 250F
Section 4
Initial Items to Inspect
•
Inspect + and – pressure sensing ports at the burner
Green tube connects to pitot tube facing inlet filters (high pressure)
Red tube connects to pitot tube facing fan wheel (low pressure)
Section 4
Initial Items to Inspect
• Inspect pilot gas plumbing into burner, igniter connector/wire, and flame rod connector/wire
Igniter boot
Flame Rod
Pilot Gas Tube
Igniter
Pilot Gas Line
Flame Rod Boot
Section 4
Initial Items to Inspect
• Ensure compressed air solenoid has been wired to the control panel and that the air supply to the application equipment has been plumbed through the solenoid
Wiring to control panel
Solenoid
Air to application equipment
Air from Compressor
Section 4
Initial Items to Inspect
• Inspect tubing running from booth wall to remote control panel
Pressure transmitter inside remote control panel
Plus pressure tube to booth wall
Minus pressure tube to atmosphere
Section 4
Initial Readings to Gather
• Incoming voltage at the top of the disconnect (needs to match name plate on the door)
Section 4 Initial Readings to Gather
• Incoming fuel pressure at the inlet of valve train (needs to match name plate on the door)
Section 4 Initial Readings to Gather
•
Control voltage
Section 4
Initial Readings to Gather
• AMU motor amps when fan is running at full speed 60hz (should match or be lower than motor name plate)
AMP rating on AMU Fan motor
AMP reading from AMU Fan VFD
Section 4
Initial Readings to Gather
• Exhaust motor amps when fan is running at full speed 60hz (should match or be lower than motor name plate)
AMP reading from Exhaust Fan VFD
AMP rating on Exhaust Fan motor
Section 4
Initial Readings to Gather
• Burner profile pressure when AMU fan is running at full speed 60hz
Section 4
Initial Readings to Gather
• Booth pressure when all doors are closed and all fans are running at full speed 60hz
Section 5
Booth Balancing
• • • • •
Understanding System Effect Adjusting VFD parameters Measuring profile pressure Adjusting profile damper Addressing doors blowing open
Section 5
The overall goals when balancing a booth: • AMU is introducing proper air flow to achieve design FPM through the booth • No motors are running above their FLA rating • Exhaust fan is not running at full speed to evacuate the air being brought in by the AMU • Air pressure across the burner in the AMU is between .5 and .7 when the booth is balanced The booth cannot be properly balance when: • AMU filters are dirty or not installed • Booth intake plenum filters are dirty or not installed • Booth exhaust plenum filters are dirty or not installed • Incorrect filters are installed (not all filters have the same initial static rating and incorrect filters may have a static rating higher than the fans capability.) • Fan rotation has not been visually inspected for correct rotation • Fan belts are loose • Ductwork is not complete • Diffuser is not correctly installed
Section 5
Start with the booth doors closed and the pressure set point at -0.050 • Booth should balance near zero and exhaust VFD should not be running at full speed • If booth is running positive, or exhaust fan is running at full speed: • Is the tube properly connected to the pressure transmitter in the remote? • Use a velometer to measure the FPM through the booth. There may be less static pressure than anticipated and the AMU speed may need to be reduced. • Is exhaust fan running the correct rotation? • Are the correct & clean exhaust filters installed? • Inspect exhaust duct for restrictions – is the ARV open? • Check for System Effect
Section 5
What is static pressure? • Resistance to airflow caused by ductwork, transitions, elbows, filters, and other accessories Fan Total Static Pressure (TSP) • Unit Internal Static (burner profile) • RTT Supplied Accessory Static • External Static • Any static associated with non-RTT supplied components (duct, transitions, 90s, turning vanes, etc.)
Section 5
Effective Duct Length
100% effective duct length
To calculate 100 % effective duct length, use a minimum of 2 1/2 duct diameters for velocities 2500 FPM or less. Add 1 duct diameter for each additional 1000 FPM
Equivalent duct diameter is equal to ( 4ab/ ) 0.5
Section 5
Position C
Discharge Elbow Position
Position D
Position B
Position A
Section 5
What is System Effect • Static pressure added to the system above that of design criteria • Intake or Discharge • Discharge is more common scenario • Duct elbows connected directly to blower discharge is the biggest contributor to system effect.
Section 5
Installed System Effect
Section 5
Installed System Effect
Section 5
Installed System Effect
Section 5
Installed System Effect
Section 5
System Effect requires more horsepower for the fan to operate at the required CFM.
Added 1/2" static (beyond design) to system. 6260 CFM @ 2.4"
RPM
• • • •
Larger more expensive motor Larger more expensive controls More electricity consumed Higher operating costs
4.2 BHP with added static
Section 5
For more detail about system effect, check out this video produced by Fan Manufacturer New York Blower
•
System Effect Video Link
Section 5
Burner Profile Opening
• 2450 Feet Per Minute = .6” w.c. air pressure drop • Adjustable plates* to achieve .6” w.c. • If pressure is low, close plates to increase • If pressure is high, open plates to decrease
Burner
•
*CT unit (no cure cycle) uses plates
• *CTC unit (with cure cycle) uses damper
Adjustable Profile Plates
Elongated Screw Slots
Fixed Profile Plates
Side View
Front View
Section 5
Measuring Burner Air Pressure Drop
Burner
Adjustable Profile Plates
Elongated Screw Slots
Fixed Profile Plates
Side View
Front View
Figure 2
Section 5
Adjust the stop on the damper during the spray mode
Manual release button • Press and hold to turn damper shaft by hand
Line on shaft indicates damper position • From the factory, damper is wide open during spray mode. • Stop prevents damper from rotating clockwise
Close the damper to increase profile pressure • Lock stop in place to prevent
damper from opening clockwise any further (keeping damper in more closed position)
Section 5
Burner Air Pressure Drop
Low
Design
High
.2 "wc
.60 "wc
.95 "wc
.462 "wc
.757 "wc
120 o Rise Pressure drop (-40 o to 80 o )
Cold Start Pressure drop -40 o F
Section 5
Burner Air Pressure Drop at Various Outdoor Air Temperatures
Section 5
Adjusting AMU speed lower • In order to lower the AMU speed, the profile pressure needs to be monitored and adjusted. • Lower AMU speed = lower profile pressure • To increase profile pressure, profile plates/damper need to be adjusted closed
Section 5
How to adjust VFD parameters • Press mode button, P0 will display • Use dial wheel to adjust to desired P number, then press set to go into that parameter • Use the dial wheel to adjust the parameter, then press set to accept it
AMU VFD Parameters to Adjust: • P77 = 2 – Unlocks the VFD • P1 = hz setting – 60hz is maximum, adjust to lower value to slow the AMU fan down • P55 = same as P1 • P125 = same as P1 • C2 = same as P1 • Ensure the value in P42 is lower than the value in P1 • When complete, set P77 back to 1 to lock the VFD
Section 5
Booth doors blowing open (after initial commissioning and booth balancing) • If doors blow open when operator presses start button, then acceleration time on exhaust fan should be decreased so that the exhaust fan ramps up slightly faster than the AMU fan. • P7 = Acceleration time (in seconds) • If doors blow open when operator presses stop button, then deceleration time on exhaust fan should be increased so that the exhaust fan ramps down slightly slower than the AMU fan. • P250 = Deceleration time (in seconds) • If doors blow open during normal operation of the booth, then: • Pressure setting on the Carel controller may be too much in the positive range (lower setting) • Exhaust filters may be clogged • Door latches may be loose or out of adjustment • Booth may not have been properly commissioned. Fan speeds need to be adjusted to meet design FPM through the booth, and proper profile pressure across the burner
Section 6
AMU and Booth Operation
• • • •
Navigating the Carel Display Understanding recipe settings
Inputting recipe settings Sequence of Operation
Section 6
The PGD is located on a remote panel and provides an end user with operating mode displays and typical set point adjustment capability. For startup or service by a qualified technician, password protected screens display additional information and allow additional set point and loop tuning adjustments. Remote Operator
Notifications Press to view details about system faults Login Press to login to adjust settings
Up Arrow Move selection up
Enter Key Accept changes
Back Key Press to go back
Down Move selection down
Section 6
Current Selected Mode Winter = run the burner in spray. Summer = do not run the burner in spray . Fan Status When the fan is proven by air pressure switches, this icon will appear Booth Pressure “Digital Magnehelic” displays the pressure inside the booth vs the pressure out side of the booth.
Burner Status When the burner is proven by the flame rod, this icon will appear Discharge Temperature Displays the temperature leaving the AMU. Mode Displays the current mode of the system (spray, flash, cure, cool, etc.) Countdown Displays the total time remaining for the recipe.
Recipe Displays the current selected recipe
Section 6
To navigate through the controller, use the up down and enter keys to make selections.
Input/Output Screens: display the current digital and analog input and output signals processed by the digital controller. Mode/Set points Screens: Allow personnel logged in with the User or Technician password to view and change unit operation modes and set points. The screens will be viewable only without entering a password. Technician Screens: Allow personnel logged in with the Technician password to view and change advanced unit modes and set points. The settings will be viewable only by users with the User password or those who are not logged in. Information Screens: Display information about the AMU and digital controller.
Section 6
Recipe Settings
Spray Temperature – Desired booth temperature during spraying operations. Cannot be cooler than outdoor air. Booth Pressure – Negative, Positive, or Balanced Zero. Normally set about zero. Positive = more air coming into the booth than being exhausted - Ensures all air coming into the booth has passed through filters - If set too positive, can cause doors to pop open Negative = more air being exhausted than being brought into the booth - If set too negative, can allow debris to be pulled into the booth through un-filtered openings
Winter/Summer – Determines if the burner should be on or off while in spray mode. If it is hot outside, select summer mode to prevent the burner from turning on. If its cold outside, select winter mode to ignite the burner.
Section 6
Recipe Settings
Flash Temperature – Desired booth temperature during flash mode. Some coatings require a period of time after being applied to “flash off”. During this time, the temperature is lower than a high heat cure temperature.
Flash Time – Amount of time the coating needs to flash off. See the spec sheet for the coating being used.
Cure 1 Temperature – Desired booth temperature during cure mode 1. See the spec sheet for the coating being used.
Cure 1 Time – Amount of time the coating needs to cure.
Cure 2 Temperature – Desired booth temperature during cure mode 2. See the spec sheet for the coating being used.
Cure 2 Time – Amount of time the coating needs to cure. (Set to zero if cure 2 is not needed)
Cool Temperature – Desired booth temperature after the cure mode has finished. Cool Time – Amount of time the coating needs to cool.
Everything above is 1 recipe. The controller is capable of storing 4 recipes labeled A, B, C, and D
Section 6
Mode/Set points Screens: Select Mode / Set points icon from the Quick Menu. The first “Active Settings” screen does not require a password to allow operator to make quick changes. Additional mode/set point screens require “OPERATOR” or higher level in order to change settings. The “OPERATOR” password is 2050.
Screen 1
Section 6
Screen 2
Screen 3
Section 6
Screen 4
Section 6
Typical Sequence of Operation
Operator presses start button at remote panel
120vac power is sent to inlet or discharge damper actuator. Actuator opens damper and the limit switch in the actuator proves its open sending a signal back to the control panel.
Section 6
Typical Sequence of Operation
After damper is proven open, the Carel controller starts the fan VFDs After the VFDs reach their minimum run speed, they send a signal back to the Carel controller to prove they are running.
If VFDs do not prove, “Blower Start Fault” will be displayed on Carel Controller
With the fans running, 120vac power is sent through the proving switch that looks at air pressure across the burner.
Burner
Pressure must be in this range for proper operation: Minimum: .5”w.c. Maximum: .7”w.c.
Adjustable Profile Plates
Elongated Screw Slots
Fixed Profile Plates
If air switch does not prove, “Low Air Flow Fault” will be displayed on Carel Controller
Side View
Front View
Figure 2
Section 6
Typical Sequence of Operation
If Carel controller is put into “Winter” mode, a call for heat signal is sent to the Fireye flame controller. 120vac power is sent through the high gas pressure switch, and high temperature limit controller.
If gas pressure switch or high limit controller are tripped, “Burner Enable Interlock” will be displayed on Carel Controller
Section 6
Typical Sequence of Operation
If 120vac passes through high gas pressure switch and high temperature limit, it will reach the Fireye Flame controller which will initiate the burner ignition sequence: 1. Energize Igniter 2. Energize Pilot Solenoid 3. Check for Flame Signal 4a. Flame Signal Proven – Energize Main Gas Valves, and De-energize Pilot & Igniter
Normal Operation Flame Fail PTFI Flame Fail Auto Flame Fail MFTI False Flame Idle
4b. Flame Signal Not Proven – De-energize Pilot Solenoid and Igniter, then issue Alarm
If flame signal is not proven, “Flame Safeguard Fault” will be displayed on Carel Controller
Section 6
Typical Sequence of Operation
After flame is proven, Carel controller begins sending DC signal to gas actuator to control flame size and therefore heat going into the booth.
• DC signal will modulate up and down based on temperature demand from the booth. • If not much heat is needed, valve will stay mostly closed and voltage will be low • If heat is needed, valve will fully open and voltage will be high.
Section 6
Typical Sequence of Operation
After spray cycle is complete, operator presses “Cure Start”
Controller begins counting down through the selected recipe: Flash time & temp first. Airflow through the booth remains the same as spray mode, temperature adjusts to flash temp set point.
Section 6
Typical Sequence of Operation
After the flash time has expired • Cure 1 timer begins counting down • AMU fan slows down • Booth exhaust fan slows down (automatically to maintain booth pressure) • Profile damper closes to maintain required pressure across the burner After Cure 1 timer expires, unit moves on to Cure 2 timer. After Cure 2 timer expires, unit moves on to Cool timer. After Cool timer expires, unit shuts down.
Section 6
Input Output Screens: Access these screens from the Input/Output icon on the Quick Menu. These values represent analog and digital inputs to the controller or internal calculated values based upon direct inputs. Use up / down arrow keys to switch between screens.
Screen 1
Section 6
Screen 2
Screen 3
Section 6
Screen 4
Screen 5
Section 6
Technician Setup Screens: Access this screen from main menu. TECH level password is required to change these settings.
Screen 1
Section 6
Screen 2
Advanced Technician Screen: Access this screen from the tech section of the quick menu. Note that Advanced Tech will be available in view only mode for all users. ADV.TECH level password is required to change these settings.
Section 6
Screen 2
Screen 3
Section 6
Information Screens: Access these screens from quick menu. Use up down arrow keys to switch between screens while screens are in select mode.
Screen 1
Section 6
Alarm Screen: This screen is accessed if an alarm condition exists (pressing blinking alarm symbol) or it can be accessed from the main menu. Some alarms require acknowledgement in order to silence the alarm horn and/or reset the alarm. Press and HOLD the alarm key in order to acknowledge an alarm. If the alarm is based upon a direct external input from a sensor or external safety control (for example a motor overload), the alarm will remain active (key will blink red) until the external input is corrected. In other cases where the c.pCO module is acting as the safety device, holding the alarm key for a slightly longer duration will reset the alarm condition. Two “Sampled Values” will also be displayed. These values show the state of the named value at the time the alarm is triggered.
Section 6
Section 7
Troubleshooting
• • • • •
Blower Start Fault Low Air Flow Fault
Burner Enable Interlock
Flame Safeguard
Preventative Maintenance
Section 7 Blower Start Fault
• This means the Carel controller told the AMU and Exhaust VFDs to run, but the VFDs didn’t send a signal back saying they’re running. • VFD may be faulted – check display on VFD to determine fault code, then check VFD manual to decipher fault code. • Fuses to VFD may be faulted – pull fuses from holder and check for continuity • Overloads on the downstream side of the exhaust VFD (for individual motor protection) may be faulted. Press reset button, then measure amps to ensure motor is not overloaded.
VFD Display
VFD Fuses
Exhaust Fan Overloads
Section 7
Low Airflow Fault
• This means the Carel controller told the VFDs to run, and the VFDs proved they were running, but the Carel controller didn’t receive a signal proving that the air pressure across the burner profile was high enough (.5” w.c. to .7” w.c.)
Causes for low air pressure drop • Clogged inlet filters • Loose drive belt • Blower rotating backwards – the blower will still move up to 60% of its capacity while rotating backwards • More external static (ductwork/transitions/turns) than what was expected when the unit was ordered • System effect – duct components installed too close to blower discharge • Profile opening around burner increased from factory setting • Leak in sensing tubes or switch diaphragm • Static probe location has been changed • Sensing tubes plugged • Blower speed reduced
Section 7
Checking low air flow pressure switch • Terminal 2 is neutral • Terminal 10 is hot when blower is proven running
Section 7
Checking low air flow pressure switch • Terminal 2 is neutral • Terminal 10A is hot when switch is proven. • If manometer reads above .3”w.c. then switch should be proven and power should be on terminal 10A
Section 7
If pressure is lower than .3”w.c. – pinch the tube between the tee and switch which will determine if drop is actually low, or if the switch is leaking.
Section 7
120
Checking high air flow pressure switch • Terminal 2 is neutral • Terminal 10A is hot when switch is proven above .3”w.c.
vac
SW-1
vdc
ohm
OL's
ST-1
L1
460/230/208 3ph 3 wire supply w/ transformer
MT- 1
L2
L3
*FU-2
*FU-2
ST1-2
no
no
53
54
AMU Starter Aux. Contact
*TR-1
FU-3
1
R 1
2
120VAC
SW-5
SUM WIN OFF
3
R 3
SW-2
12 12 R
11 11 R
SW-6
ST1-1
P-1A
P-1
10A
no
no
10
4
DM-1
H N
*LTS-1
OL's
ST-1
c
no
95
96
5
6
7
7 8
TL-1
*T-1
P-3
*P-2
14A
13
14
15
6
2
1
A
S2
3
TR-2
19
S1
4
V-1
FS-1
5
V-2
Standard AMU 120 VAC control circuit
*V-3
18
V-4
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