Honeywell Multiple Meter Units Installation Instructions Manual page 10

HONEYWELL MULTIPLE METER UNITS (MMU)
a. The sensor leads cannot be installed randomly and should be bundled
together when they are routed to the meters which are mounted on the door
of the MMU. They shall be secured and routed away from the power wiring
and the communication cabling. They shall be bundled with appropriate
means such as clamps, wire ties, spiral wrap, etc.
b. To avoid damage to the bundled conductors when the door is opened and
closed, tubing, guides, spiral wrap, clamps, or other approved means shall
be used. This is required to provide proper protection and stress relief for the
conductors.
c. All wiring is to be routed away from any points that may possibly damage or
abrade the insulation - such as sharp edges, screw threads, burrs, or any
other item that may have been installed in the MMU enclosure. The final wir-
ing must allow the door to freely open and close without coming in contact
with anything that could damage it.
NOTE: Following the proper wiring procedures will help to assure a satisfactory
installation.
NOTE: Units housed in UL type 1 enclosures must only be installed in indoor loca-
tions, where they will not be affected by the elements
6.2 Grounding
The meters and enclosure must be prop-
erly grounded for safety. A protective earth
ground lug is provided for this purpose.
Failure to ground the enclosure creates a
possible shock hazard. There are two ter-
minals that attach to the base ground stud.
Do not operate without protective earth
wire attached securely to the PE terminal
screw. After installing the protective earth
wiring, secure the screw tightly (7 N-m
torque).
6.3 RS485 Communication Wiring
The RS485 Communication wiring is installed by connecting the leads to the
appropriate terminals on the 3-position RS485 terminal strip mounted on the back
panel of the enclosure. The wiring terminals are labeled GND, HIGH, and LOW to
correspond to the appropriate connections of the communication cabling. Tighten the
terminals to 9 in-lbs of torque.
for communication wiring in MMU enclosures. The communication cabling must be
routed away from the mains wiring.
62-0400-01
Class 1 rated, Belden 1120A cable (600V) is to be used
10
Fig. 5. Base Ground Stud.