4. INSTALLATION INSTRUCTIONS
Hazard of Electrical Shock, Burn or Explosion
All installation, servicing and testing referred to in this manual must be
performed by qualified personnel. All power should be disconnected
prior to removing covers or enclosures and where live conductors
may otherwise be exposed.
Failure to observe these precautions may result in death or severe
personal injury and damage to equipment. Before placing an
intentional ground fault on the power system, check that a fault does
not already exist. Any test ground fault equipment must be rated for
full system voltage and be fused for protection.
danger
The internal electronics have been encapsulated in epoxy to improve the performance in high vibration
environments. Try to keep the exposure to mechanical shock and vibration to a minimum and place the mGARD-100
in a clean dry enclosure. Locate the relay close to the isolating device (circuit breaker or contactor) that is protecting
the circuit being monitored.
When using an interposing current sensor, keep the distance between the relay and the sensor as short as possible.
Use twisted cable and increase the gauge of the conductor as per the table below:
Table 4.0 ZSCS secondary wire run-length
Up to 300 Ft. / 91m.
16
301ft / 92m to 450ft / 137m
14
maximum cable run in feet/meters
minimum wire gauge
Provide maximum clearance between the mGARD-100 (and the interposing ZSCS if required) and any strong
magnetic flux producing devices such as power transformers, autotransformers, control transformers, reactors, and
high power conductors and bus work.
4.1 MOUNTING
Refer to Figure 8.0 for mounting dimensions of the mGARD-100 relay. The mGARD-100 is designed to be mounted
with either mounting screws or on a 35 mm DIN rail.
Two #8-32 x 3/4” (M4 x 20) mounting screws are required for screw mounting.
For DIN rail mounting the rail should be bolted to a flat surface. Install the DIN rail horizontally. Allow at least ¾” (20
mm) of rail to extend beyond each end of the relay. Secure the relay to the DIN rail ensuring the release latch at the
bottom of the relay engages the rail. If the relay is to be mounted in any other position take appropriate steps to
prevent the relay from disengaging from the DIN rail.
