77C-LR - 777/77C Series

littelfuse Motor and Pump Protection Relays
The 777/ 77C is a fully programmable electronic overload relay designed to protect any motor drawing 2-800 full load amps (external CTs are required above 90 amps). The 777-HVR-SP and 77C (family of products) are for single-phase 100-240VAC applications. Common applications include conveyor systems, HVAC equipment, saws and grinders, fan motors, and almost any pumping application.

All of the overload relays provide unsurpassed protection by combining overload, underload, and voltage in one package. For standalone applications, the units incorporate a 3-digit LED display that is used for programming, providing real-time operational information and displaying diagnostic codes to aid in troubleshooting a fault condition. The units also feature a communications port that can be used with communication modules listed in the 777 accessories section to form a Modbus, DeviceNet™, Profibus, or Ethernet network. Up to 99 units can be remotely monitored and controlled from a PC, PLC, or SCADA system, and data logging through a PC with the optional Solutions software. This capability allows for a simple, cost-effective way to meet new requirements for arc-flash safety.

Property (Mouseover for details) Value
Input Voltage (V) 100 to 240VAC
Maximum Input Power 10W
Input AC Line Frequency (Hz) 50/60Hz
Output Form SPDT - Form C
Output Load Rating (VA) Pilot Duty: 480VA @ 240VAC B300; General Purpose: 10A @ 240VAC
Full Load Amp Range (A) 1.0 - 2.5A (loos required); 2.0 - 9.0A (direct)
Timing Accuracy (%) 5% ± 1s
Rapid Cycle Timer (s) 0 2 - 500s
Restart Delay Range After Under/Overcurrent: 2 - 500m/s; # of Restarts: Overcurrent: 0 1 oc1 2 oc2 3 oc3 4 oc4 A (Automatic) OCA; Undercurrent: 0 1 2 3 4 A (Automatic)
Repeat Accuracy (%) Voltage: ±0.5% of nominal voltage; Current: ±1% (direct no external CTs)
Overvoltage Trip Voltage (%) 85V - HV setting
Undervoltage Trip Voltage LV setting - 264V
Voltage Accuracy (%) ±1%
Overcurrent Trip Point (20A - 100A) … MULT of 80 - 120% of CT primary
Overcurrent Trip Class 5 J5 10 J10 15 J15 20 J20 30 J30 or Lin (linear)
Undercurrent Trip Point (0 10 - 98 Amps) … MULT or 40 - 100% of CT primary
Undercurrent Trip Delay (s) 2 - 60s
Current Accuracy (%) ±3% (<100 amps direct)
Ground Fault Accuracy (%) ±15%
Sensor Hole Size Max conductor size: 0.65 in (with insulation)
Short Circuit (kA) 100kA per UL 10kA per CSA
Surge Protection IEC: 61000-4-5 Level 3 2kV line-to-line; Level 4 4kV line-to-ground
Protection Class IP20 NEMA 1
Pollution Degree 3
CT Ratio 1 or 2
Address A01 - A99
Life Electrical: 1 x 105 operations at rated load; Mechanical: 1 x 106
Termination Type 7 in.-lbs.
Mounting Method Surface mount (4 - #8 screws) on DIN rail mount
Operating Temperature -20° to 70°C (-4° to 158°F)
Storage Temperature (F/C) -40° to 80°C (-40° to 176°F)
Humidity 10-95% non-condensing per IEC 68-2-3
Dimensions 3.05 H x 3.85 W x 5.05 D in. (77.5 x 97.8 x 128.3 mm)
Weight (lbs/g) 1.20 lbs (19.2 oz. 544.3 g)