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Learn how Tsubaki is supporting Meat & Poultry Companies.

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U.S. Tsubaki SHOCK RELAY monitors the change in motor current that closely approximates the torque output of the motor. Should the motor current exceed the preset LOAD CURRENT point for a preset length of SHOCK TIME (continuous overload time), the SHOCK RELAY will shut down the motor power supply.
The TSB151 and TSB152 series SHOCK RELAY allows easy connection into new or existing applications. For single or three phase motors, simply wire the current transformer that we supply into one line of the motor and the SHOCK RELAY into the control circuit (stop-start circuit).
The SHOCK RELAY is powered by the same voltage as the control circuit to the motor starter, usually 115V or 230V single phase. If a different control voltage is used, a step down transformer may be required.
The supplied current transformer is then connected in one line of the motor that is being monitored. Motor voltages above 600 volts require special considerations.
Unit of Measure



N/A 0.25 to 16 amps

Load Current Range

N/A 30 to 130 %

Start Time Setting Range

N/A 0.2 to 20 s

Shock Time Setting Range

N/A 0.2 to 3 s

Input Voltage for Operation

N/A 115/230 Volt 50/60 Hz

Allow. Input Voltage Fluctuation

N/A 10 %

Meter Fine Tuning Adjustment

N/A Yes
Output Contact1 N/A Transfer Contact 250VAC 0.2A at inductive load

Test Button

N/A Yes

Withstanding Voltage

N/A 1500 VAC at 60 Hz for 1 min. between terminal and enclosure

Surface Color

N/A Munsell 7.5BG4/1.5


N/A 2.200 lb

Power Consumption

N/A 1.2 VA

Operating Temperature Range

N/A 14 to 122 ºF

Operating Humidity

N/A 85% R.H. or less

Max. Elevation

N/A 1000 m


N/A Free of corrosive gas and dust
  • 1 If the starter coil in the magnetic contactor (MC) of the monitored motor exceeds the Shock Relay output contact’s capacity, an auxiliary relay must be installed to prevent damage to the Shock Relay. The instruction manual included with each Shock Relay details how to add this auxiliary relay if required.
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