ETC H550

Ground fault indication
relay - H550
Code requirements
Features
NFPA 70, the U.S. National Electrical Code (NEC) requires
that services of 1000 amps and larger in capacity which
operate at more than 150 volts from line-to-neutral must be
provided with ground fault equipment. Generator sets rated
at 100 amps and larger which serve as emergency power
must be provided with ground fault indication equipment.
Health care facilities that utilize ground fault protection
equipment must be provided with a coordinated multi-level
ground fault system.
Suitable for indicating a ground fault condition on a
generator set which is either locally or remotely
grounded.
Cummins Power Generation ground fault indication
equipment is designed for use in emergency/standby power
systems, for indication of ground fault conditions during
generator set operation.
Ground fault current settings - 100-1200 A, in 10
discrete settings: 100, 150, 200, 250, 300, 450, 600,
750, 800, 1200 A.
Power - Operates on 24 VDC (nominal) control power fully functional at voltages from 18-30 VDC.
Direct connection - Suitable for direct connection to
generator sets operating at voltages up to 600 VAC (line
to line).
Monitoring - Provides continuous monitoring of
neutral-to-ground with LED indication for open
connection.
Factory mounted controls - Available factorymounted and interconnected to Cummins Power
Generation Detector™ series PowerCommand® controls.
Link reconnection - For use with either 3-pole (solid
neutral or 4-pole (switched neutral) transfer switches.
Indicating lamps - For Relay on (green), ground fault
current over setting (red), loss of ground connection
(red).
Time delay settings - 0-1.0 seconds.
Circuit board - One-piece molded case fully potted.
Contacts - One set of form C output, rated 1100 VA,
250 VAC, 5 A continuous, 3 A breaking @ 240 VAC.
“Test” - Push-button.
“Reset” - Push-button.
Percent full scale metering output - 0-1 mA full
scale.
Bonding jumper - Sized per NEC requirements.
©2007|Cummins Power Generation Inc.|All rights reserved|Specifications subject to change without notice|Cummins Power Generation
and Cummins are registered trademarks of Cummins Inc. “Our energy working for you.”, PowerCommand and Detector are trademarks of
Cummins Power Generation.
AC-160d (7/07) Page 1 of 4
Construction
System operation
The relay is provided in a non-conducting phenolic case,
with provisions for panel mounting or mounting to a
standard DIN rail (panel mounting is recommended for
mounting on a generator set). Relay components are
fully potted with epoxy resin for vibration resistance and
durability.
The ground fault relay continuously monitors the voltage
across the neutral-to-ground bonding jumper and lights
the ground fault alarm lamp on the generator set control
when the connection is broken.
The relay includes an integral terminal block assembly,
which accepts wires up to 12-gauge.
Relay function selection link (auto/hand reset).
Environmental range - Operating -10 °C to +60 °C,
storage -40 °C to 80 °C.
Power input - 5 VA at 24 VDC.
Transfer switch type selection link - (3-pole or
4-pole).
When the generator set is running, the relay continuously
monitors the line-to-neutral generator set connection and
lights the ground fault alarm lamp on the generator set
control when a ground fault condition is sensed.
Alarm condition can be cleared by pushing the reset
switch on the generator set control panel. Actual ground
fault current level can be monitored with a 0-1 mA meter,
directly from the relay. A push button test switch is
provided to simulate ground fault conditions and operate
the relay and indication circuitry. Addition of the autoreset link activates automatic reset of the relay after the
ground fault condition has cleared.
System schematic
Separately derived system connections (local grounding connection).
Neutral-to-ground bonding jumper must be sized per code requirements. For non-separately derived systems
(3-phase/4-wire systems with 3-pole transfer switch), the ground connection and the neutral-to-ground bonding jumper
on the generator set are removed, and the 3-pole ATS link is added to the ground fault relay. For non-separately
derived systems a label must be applied to the service entrance switchboard, indicating that removal of the equipmentbonding jumper can cause hazardous operating conditions.
Our energy working for you.™
www.cumminspower.com
©2007|Cummins Power Generation Inc.|All rights reserved|Specifications subject to change without notice|Cummins Power Generation
and Cummins are registered trademarks of Cummins Inc. “Our energy working for you.”, PowerCommand and Detector are trademarks of
Cummins Power Generation.
AC-160d (7/07) Page 2 of 4
Outline detail
Weight: 19 oz (540 grams)
Interconnection detail
* Required only with separately derived systems. Bonding jumper is included in kit.
Field Installation kits
Description
Frame 4 or 5 alternators
Frame 6 or 7 alternators
Instruction sheet
PowerCommand 3100 control
0300-4582-05
0300-4582-06
C489
Detector series control
0300-4607-05
0300-4607-06
C488
PowerCommand 2100 control
0179-3244-05
0179-3244-06
C645
Certification
ISO9001 - This product was designed
and manufactured in facilities certified
to ISO9001.
Our energy working for you.™
www.cumminspower.com
©2007|Cummins Power Generation Inc.|All rights reserved|Specifications subject to change without notice|Cummins Power Generation
and Cummins are registered trademarks of Cummins Inc. “Our energy working for you.”, PowerCommand and Detector are trademarks of
Cummins Power Generation.
AC-160d (7/07) Page 3 of 4
Americas
1400 73rd Avenue N.E.
Minneapolis, MN 55432 USA
Phone: 763 574 5000
Fax: 763 574 5298
Europe, CIS, Middle East and Africa
Manston Park Columbus Ave.
Manston Ramsgate
Kent CT 12 5BF United Kingdom
Phone 44 1843 255000
Fax 44 1843 255902
Asia Pacific
10 Toh Guan Road #07-01
TT International Tradepark
Singapore 608838
Phone 65 6417 2388
Fax 65 6417 2399
Warning: Back feed to a utility system can cause electrocution and/or property damage. Do not connect generator sets to any building
electrical system except through an approved device or after building main switch is open.
Warning: For professional use only. Must be installed by a qualified service technician. Improper installation presents hazards of electrical
shock and improper operation, resulting in severe personal injury and/or property damage.
Our energy working for you.™
www.cumminspower.com
©2007|Cummins Power Generation Inc.|All rights reserved|Specifications subject to change without notice|Cummins Power Generation
and Cummins are registered trademarks of Cummins Inc. “Our energy working for you.”, PowerCommand and Detector are trademarks of
Cummins Power Generation.
AC-160d (7/07) Page 4 of 4