Symcom 77C-KW/HP, 77C-LR-KW/HP Catalog Page

2880 North Plaza Drive • Rapid City, SD 57702
[phone] • [phone] • FAX [phone]
www.symcominc.com • email:[e-mail]

9/04

Features

UL listed as an
overload relay.

15 parameters can
be programmed for
maximum protection.

Digitally programmable
for precise customization.

Last fault memory
provides instant
troubleshooting
diagnostics.

Recordable voltage,
current, last four faults,
KWh usage, and power
factor with communications
package.

Compact design saves
precious panel space.

Protects Single-Phase
motors from:

• Overload

• Underload

• Jams

• Low voltage

• High voltage

• Rapid cycling

Additional Features:

• Fully programmable

• CSA approved

• CE compliant

• UL and cUL listed

• Automatic or manual reset

• Tamper guard

• RS485 communication port
(with pn RS485MS-2W)

• Remote reset

• Surface and DIN rail mount

• Alphanumeric LED
diagnostic display

• Last fault memory

• 5-year warranty

• Made in USA

The Model 77C-KW/HP has important advantages over current monitors in
many protection applications. Any motor load that has a small or very non-linear
change in current vs.load requires the use of a power monitor for underload, dry
run and dead-head protection. The change in power vs. load is more linear for
most motor loads and is greater in magnitude than the change in current in all
motor loads. This is because power measurements take into account both
power factor (pf) and current.

Small motors, those under 3 hp and especially fractional horsepower, exhibit
small changes in current vs. load, but the change in power is large. When
larger motors are derated (run below their rated horsepower) the change in
current is small vs. load, but again, the change in power is large and linear.
Other typical applications include slower speed mixer or agitator motors up to 50
hp and beyond. These motors and others that run slower than around 3400 rpm
usually have small current changes vs.load.

Magdrive and can pumps tend to be small horsepower, positive displacement­type pumps. These pumps need the high sensitivity of a power monitor to
protect them from dry run using the underpower feature and dead-head
conditions using the underpower feature if the motor decouples from the pump,
and the overpower feature if the motor does not decouple.

The built-in UL Listed/CSA approved overload, current unbalance, reverse
phase, single-phase and other protection features are significant benefits over
similar products. The Modbus communications capability allows this device to
be directly integrated with the SymCom RM-1000 and RM-2000 remote
displays or other remote monitoring and control equipment.

77C-KW/HP

77C-LR-KW/HP

Overload Relay

•

Engineered

Protection

2880 North Plaza Drive • Rapid City, SD 57702
[phone] • [phone] • FAX [phone]
www.symcominc.com • email:[e-mail]

9/04

SymCom warrants its microprocessor-based products against defects in material or workmanship for a period of five (5) years from the
date of manufacture.All other products manufactured by SymCom shall be warranted against defects in material and workmanship for
a period of two (2) years from the date of manufacture.For complete information on warranty, liability, terms, returns, and cancellations,
please refer to the SymCom Terms and Conditions of Sale document.

Specifications

•

Operating Points

•

Special Options

77C-KW/HP & 77C-LR-KW/HP

Overload Relay

* If J Prefix is displayed in trip class setting, jam protection is

enabled. If programmed to Lin position, overcurrent trip
delays are fixed linear-type delays set in OPT1 position.

**RD2 & RD3 can be changed from minutes to seconds

under program position OPT2.

0 Minutes Minutes
1 Minutes Seconds
2 Minutes Minutes
3 Seconds Seconds

SETTING RD2 RD3

SPECIFICATIONS OVERLOAD RELAY

Electrical

Input Voltage 100-240 VAC, 1Ø
Frequency 50-60 Hz
Motor Full Load Amp Range - 77C-KW/HP 2-25 Amps, 3Ø(Loops Required)

26-90 Amps, 3Ø(Direct)
91-800 Amps, 3Ø(External CT's)

Motor Full Load Amp Range - 77C-LR-KW/HP 1.0 Amps - 2.5 Amps (1 Loop)

2.0 Amps - 9.0 Amps (Direct)
Short Circuit Withstand Rating 100kA per UL and CSA
Power Consumption 5W (Maximum)
Output Contact Rating SPDT (Form C) Pilot duty rating: 480 VA @ 240 VAC

General purpose: 10A @ 240 VAC

Expected Life

Mechanical

1 x 106 operations

Electrical

1 x 105 operations at rated load

Accuracy at 25° C (77° F)

Voltage ±1%
Current ±3% (Direct, No External CT's)
Timing 5% ± 1 second

Repeatability

Voltage ± 0.5% of nominal voltage
Current ± 1% (Direct, No External CT's)

Safety Marks

UL UL508, UL1053
CE IEC 60947-1, IEC 60947-5-1

Standards Passed

Electrostatic Discharge (ESD) IEC 1000-4-2, Level 3, 6kv contact, 8kv air
Radio Frequency Immunity (RFI), Conducted IEC 1000-4-6, Level 3 10V/m
Radio Frequency Immunity (RFI), Radiated IEC 1000-4-3, Level 3 10V/m
Fast Transient Burst IEC 1000-4-4, Level 3, 3.5 kv input power
Surge

IEC 1000-4-5

Level 3, 2kv line-to-line; Level 4, 4kv line-to-ground

ANSI/IEEE C62.41 Surge and Ring Wave Compliance to a level of 6kv line-to-line
Hi-potential Test Meets UL508 (2 x rated V +1000V for 1 minute)
Vibration IEC 68-2-6, 10-55Hz, 1mm peak-to-peak, 2 hours, 3 axis

Shock IEC 68-2-27, 30g, 3 axis, 11ms duration, half-sine pulse

Mechanical

Dimensions 3.1"H x 5.1 " D x 3.9"W
Terminal Torque 7 inch•lb
Enclosure Material polycarbonate
Weight 1.2 lbs

Maximum Conductor Size Through 777 0.65" with insulation

Environmental

Temperature Range Ambient Operating: -20° - 70° C (-40° - 158°F)

Ambient Storage: -40° - 80° C (-40° - 176°F)
Pollution Degree 3
Class of Protection IP20, NEMA 1

Relative Humidity 10-95%, non-condensing per IEC 68-2-3

Programmable Operating Points Range

LV- Low Voltage Threshold 85V - HV Setting
HV- High Voltage Threshold LV Setting - 264V
MULT- # of Conductors or CT Ratio (XXX:5) 77C: 1-10 Conductors or 100-800 Ratio 77C-LR: 1 or 2
OC- Overcurrent Threshold (20-100A) ÷ MULT or 80-120% of CT Primary
CUB- Current Unbalance Threshold 2 - 25% or 999
TC- Overcurrent Trip Class * 5, J5, 10, J10, 15, J15, 20, J20, 30, J30, or LIn (linear)
RD1- Rapid Cycle Timer 0, 2 - 500 Seconds
RD2- Restart Delay After All Faults Except Undercurrent 2 - 500 Minutes/Seconds

(motor cool down timer)**

RD3- Restart Delay After Undercurrent 2 - 500 Minutes/Seconds

(dry well recovery timer)
#RU- Number of Restarts After Undercurrent 0, 1, 2, 3, 4, A(Automatic)
ADDR- RS485 Address A01- A99
#RO-Number of Restarts After Overcurrent 0, 1, 2, 3, 4, A(Automatic)
LP/PWS (PWS = LP Range) 1 = 0.01 - 0.99 KW 5 = 0.01 - 0.99 HP

2 = 1.00 - 9.95 KW 6 = 1.00 - 9.95 HP
3 = 10.0 - 99.5 KW 8 = 10.0 - 99.5 HP
4 = 100 - 650 KW 9 = 100 - 650 HP

3.050"
(77.47)

2.650"
(67.31)

2.280"
(57.91)

3.850" (97.79)

3.600" (91.44)

3.100" (78.74)

0.002" (5.08)

5.050"

(128.27)

4.700"

(119.38)

1.200"
(30.48)

D. 0.650" (16.51)

3.600" (91.44)

3.850" (97.79)

ABC

SYMCOM RECOMMENDS USING CTs WITH TERMINALS
TO SIMPLIFY INSTALLATION.

NOTE: PHASES A & C ARE INACTIVE. USE PHASE B FOR ALL ACTIVE
CURRENT MEASUREMENTS. CT SECONDARY MUST MAKE FIVE PASSES
THROUGH THE PHASE B CONDUCTOR WINDOW.
NOTE: OTHER NECESSARY CONNECTIONS ARE NOT SHOWN

L1

CONTACTOR

COIL

CONTROL
POWER

START

STOP HAND

AUTOPILOT

M

A

TO MOTOR

BC

OFF

240 VAC
OR LESS

NOTE: PHASES A&C
ARE INACTIVE

L2