U.S. TSUBAKI SHOCK RELAY
TSB151A, TSB152A
Overload Protection Plus Pre-Alarm Setting
POWER INDICATOR Indicates that the power supply is on. TRIP INDICATOR Lamp comes on when SHOCK RELAY trips. TEST BUTTON This switch is used to verify SHOCK RELAY operation. The TSB151A and TSB152A have a test switch for both the alarm set point and the overload set point. RESET BUTTON (manual) Reset can be done quickly whenever a restart is desired. SHOCK TIME This presets the overload period. Range is variable from 0.2 to 3 seconds. Every momentary load over the preset current with a shorter period than the preset period is ignored. When the overload equals the preset period, the SHOCK RELAY will trip immediately to break the power supply to the motor.
ACTUAL LOAD METER Actual current of the motor is indicated in percentages, which makes it easy to set “LOAD CURRENT,” regardless of the value of the actu- al current load. LOAD CURRENT This presets the load current at the optimum setting in the range from 30% to 130% of the motor’s current. When the actual load current exceeds the preset current for the preset SHOCK TIME, the SHOCK RELAY trips to break the motor circuit. ALARM SET POINT This presets the level at which an Alarm will sound. The Alarm can provide prior warning of an impending problem that may be correctable prior to the need to shut down the equipment.
START TIME When starting a motor, the starting current value is greater than the running current. This starting current value continues until the motor reaches normal speed. During this starting period, the time of which mainly depends on the type of load, the function of detecting the overload current is disabled. Adjustable range is from 0.2 to 20 seconds.
TYPICAL CONNECTING DIAGRAM
DIAGRAM OF OPERATION
TSB151A, TSB152A
M Motor MC Electromagnetic Contactor TH Thermal Overload Relay CB Circuit Breaker
Note: Refer to Specifications on page D-15.
Dimensions and current transformer selection are the same as for the TSB151 and TSB152. Refer to page D-8.
D-11
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