Wiring - Honeywell 7800 Series Product Data

Vibration
Do not install the RM7896 where it could be subjected to
vibration in excess of 0.5G continuous maximum vibration.
Weather
The RM7896 is not designed to be weather tight. If installed
outdoors, the RM7896 must be protected by an approved
weather-tight enclosure.
Mounting Wiring Subbase
NOTE: For installation dimensions, see Fig. 1 or 2.
1. Mount the subbase in any position except horizontally
with the bifurcated contacts pointing down. The standard
vertical position is recommended. Any other position
decreases the maximum ambient temperature rating.
2. Select a location on a wall, burner or electrical panel.
The Q7800 can be mounted directly in the control
cabinet. Be sure to allow adequate clearance for
servicing, installation, access and removal of the
RM7896, dust cover, flame amplifier, flame amplifier
signal voltage probes, Run/Test Switch, electrical signal
voltage probes and electrical field connections.
3. For surface mounting, use the back of the subbase as
a template to mark the four screw locations. Drill the
pilot holes.
4. Securely mount the subbase using four no. 6 screws.

WIRING

1. For proper wiring, refer to Fig. 7 or 8. For proper
remote wiring of the Keyboard Display Module, refer to
the Specifications for the Keyboard Display Module
(65-0090), Communication Interface Base Unit (63-2278),
Data ControlBus Module™ (65-0091) or Extension
Cable Assembly (65-0131).
2. Disconnect the power supply from the main disconnect
before beginning installation to prevent electrical shock
and equipment damage. More than one disconnect
may be involved.
3. All wiring must comply with all appropriate electrical
codes, ordinances and regulations. Wiring, where
required, must comply with NEC Class 1 (Line Voltage)
wiring.
4. Recommended wire size and type: use no. 14, 16, or
18 copper conductor (TTW60C or THW75C or
THHN90C) 600 volt insulation wire for all Line Voltage
terminals. For high temperature installations, use wire
selected for a temperature rating above the maximum
operating temperature. All leadwires must be moisture
resistant.
7800 SERIES RM7896A,B,C,D RELAY MODULE
5. Recommended grounding practices:
a. Use the earth ground to provide a connection
between the subbase and the control panel or the
equipment. The earth ground wire must be capable
of conducting the current to blow the 20A fuse (or
breaker) in event of an internal short circuit. The
RM7896 needs a low impedance ground connection
to the equipment frame which, in turn, needs a low
impedance connection to earth ground. For a ground
path to be low impedance at RF frequencies, the
connection must be made with minimum length
conductors that have a maximum surface area.
Wide straps or brackets are preferred rather than
leadwires. Be careful to verify that mechanically
tightened joints along the ground path, such as pipe
or conduit threads or surfaces held together with
fasteners, are free of nonconductive coatings and
are protected against mating surface corrosion.
b. RM7896—Each RM7896 will have an earth ground
terminal that must be grounded to the metal control
panel with wire as short as practical. Each ground
wire must be capable of carrying a fault current
equal to the rating of the protective fuse (20A). A
number 14 copper conductor is adequate, but wide
straps or brackets are preferred rather than
leadwires.
6. Recommended wire routing for flame detector
leadwires:
a. Do not run high voltage ignition transformer wires in
the same conduit with the flame detection wiring.
b. Do not route scanner wires in a conduit with line
voltage circuits.
c. Enclose scanner wires without armor cable in metal
cable or conduit.
d. Follow directions given in flame detector Instructions.
7. Maximum wire lengths:
a. For the RM7896, the maximum length of leadwire to
the terminal inputs is 300 feet (Control and Airflow
Interlock).
b. For the flame detector leadwires, the maximum
flame sensor leadwire length is limited by the flame
signal strength.
8. Make sure loads do not exceed the terminal ratings.
Refer to the label on the RM7896 or to the ratings in the
Specifications, see Table 1.
9. Check the power supply circuit. The voltage and
frequency tolerance must match those of the RM7896.
A separate power supply circuit may be required for the
RM7896 with the required disconnect means and
overload protection added.
10. Check all wiring circuits and complete the Static
Checkout, see Table 4, before installing the RM7896 on
the subbase.
11. Install all electrical connectors.
12. Restore power to the panel.
11
65-0193