


The 355 series is a three-phase voltage monitor with adjustable trip and restart delay, adjustable voltage unbalance, and multiple diagnostic lights. It is ideal for heavy-duty applications that need both protection and simple user-friendly diagnostics. Suitable applications include pump panels, commercial HVAC, oil rigs, and many more. The 355 series uses microcontroller technology to monitor incoming voltage and de-energize its output relay if power problems exist. It can protect motors from damage caused by single-phasing, high- and low-voltage, phase reversal, and voltage unbalance. These relays have four diagnostic LEDs that clearly show overvoltage, undervoltage, voltage unbalance, reverse-phase, and normal conditions. The adjustable trip and restart settings prevent nuisance tripping due to rapidly fluctuating power line conditions and allow staggered start-up of multiple motors after a fault to prevent a low-voltage condition.
Series 355 models include the 355-200, which is equipped with a heavy-duty 10 A general purpose SPDT relay. The 355-400 and 355-600 models are equipped with a 470 VA @ 600 V ac pilot duty SPDT relay. A high-voltage (600 V) DPDT relay output option is available with the 400 V model.
- Proprietary microcontroller-based circuitry
- Advanced LED indication
- Adjustable trip and restart delay settings
- 600 V rated relay contacts available on some models
- 600V rated relay contacts available on some models
- Constantly monitors three-phase voltage to protect against harmful line conditions even before the motor is started
- Provides diagnostics that can be used for troubleshooting and to determine relay status
- Prevents nuisance tripping and allows staggered start-up of multiple motors after a fault to prevent a low-voltage condition
- Eliminates the need for a control transformer to step voltage down to 120–240 V for a control circuit
- Eliminates the need for a control transformer to step voltage down to 120 - 240V for a control circuit
355 Parts
Filters
Part Number | Actions | Input Voltage (V) | Output Form | Termination Type | Mount Method | Dimensions | Weight (kg) | Input AC Line Frequency (Hz) | Maximum Input Power (W) | Output Load Rating (VA) | Overvoltage Reset Voltage (%) | Overvoltage Trip Voltage (%) | Repeat Accuracy (%) | Restart Delay Range | Storage temperature (°C) | Trip Delay Range | Trip Point Accuracy (%) | Undervoltage Reset Voltage (%) | Undervoltage Trip Voltage (%) | Voltage Unbalance Reset (%) | Voltage Unbalance Trip Point (%) |
---|
Part Number | Actions | Input Voltage (V) | Output Form | Termination Type | Mount Method | Dimensions | Weight (kg) | Input AC Line Frequency (Hz) | Maximum Input Power (W) | Output Load Rating (VA) | Overvoltage Reset Voltage (%) | Overvoltage Trip Voltage (%) | Repeat Accuracy (%) | Restart Delay Range | Storage temperature (°C) | Trip Delay Range | Trip Point Accuracy (%) | Undervoltage Reset Voltage (%) | Undervoltage Trip Voltage (%) | Voltage Unbalance Reset (%) | Voltage Unbalance Trip Point (%) | |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
190 - 240 Vac | SPDT | Torque: 7 in-lbs; Wire Size: 12 - 18 AWG | 2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm) | 0 Kg (kilogram) | 50 / 60 (50 will increase all delay timers by 20%) | 6 | Pilot Duty: 480 VA @ 240 Vac; General Purpose: 10 A or 1 hp @ 240 Vac | 107% | 110% | ±0.1% | After a Fault or power loss: Manual; 2 - 300 s adjustable | Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 s | ±1% | 93% | 90% | Trip setting minus 1% | 2 - 8% adjustable | |||||
380 - 480 Vac | SPDT | Torque: 7 in-lbs; Wire Size: 12 - 18 AWG | 2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm) | 0 Kg (kilogram) | 50 / 60 (50 will increase all delay timers by 20%) | 6 | Pilot Duty: 470 VA @ 600 Vac; General Purpose: 10 A | 107% | 110% | ±0.1% | After a Fault or power loss: Manual; 2 - 300 s adjustable | Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 s | ±1% | 93% | 90% | Trip setting minus 1% | 2 - 8% adjustable | |||||
475 - 600 Vac | SPDT | Torque: 7 in-lbs; Wire Size: 12 - 18 AWG | 2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm) | 0 Kg (kilogram) | 50 / 60 (50 will increase all delay timers by 20%) | 6 | Pilot Duty: 470 VA @ 600 Vac; General Purpose: 10 A | 107% | 110% | ±0.1% | After a Fault or power loss: Manual; 2 - 300 s adjustable | Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 s | ±1% | 93% | 90% | Trip setting minus 1% | 2 - 8% adjustable | |||||
380 - 480 Vac | DPDT | Torque: 7 in-lbs; Wire Size: 12 - 18 AWG | 2.93 H x 5.27 W x 2.95 D in. (74.4 x 133.9 x 74.9 mm) | 0 Kg (kilogram) | 50 / 60 (50 will increase all delay timers by 20%) | 6 | Pilot Duty: 470 VA @ 600 Vac; General Purpose: 10 A | 107% | 110% | ±0.1% | After a Fault or power loss: Manual; 2 - 300 s adjustable | Under/Over and Unbalance Voltage: 2 - 30 s adjustable; single-Phase faults (>25%UB): 2 s | ±1% | 93% | 90% | Trip setting minus 1% | 2 - 8% adjustable |
355 Applications
- Pump panels
- Commercial HVAC
- Oil rigs
- Heavy-duty applications that need both protection and simple user-friendly diagnostics