Final Wiring Check - Honeywell 7800 Series Installation Instructions Manual

Ground Type
Earth ground (subbase and relay
module).
Signal ground (Keyboard Display
Module, Data ControlBus™
Module, Modbus™ Module.
9. Maximum wire lengths:
a. RM7898 leadwires: The maximum leadwire
length is 300 feet to terminal inputs (Control,
Running/Lockout Interlock).
b. Flame Detector leadwires: The maximum flame
sensor leadwire length is limited by the flame signal
strength.
c. Remote Reset leadwires: The maximum length of wire
is 1000 feet (305 meters) to a Remote Reset push
button.
d. Data ControlBus™ Module: The maximum Data
ControlBus™ Module cable length depends on
the number of system modules connected, the
noise conditions and the cable used. The
maximum length of all Data ControlBus™
Module interconnecting wire is 4000 feet (1219
meters).
RM7898A 7800 SERIES VALVE PROVING PRIMARY RELAY MODULES
Table 2. Recommended Grounding Practices.
1. Use to provide a connection between the subbase and the control panel of the
equipment. Earth ground must be capable of conducting enough current to
blow the
15A, type SC, fast blow fuse (or breaker) in the event of an internal short circuit.
2. Use wide straps or brackets to provide minimum length, maximum surface area
ground conductors. If a leadwire is required, use 14 AWG copper wire.
3. Make sure that mechanically tightened joints along the ground path are free of
nonconductive coatings and protected against corrosion on mating surfaces.
Use the shield of the signal wire to ground the device to the signal ground terminal
3(c) of each device. Connect the shield at both ends of the daisy chain to earth
ground.
9
Recommended Practice
10. Be sure loads do not exceed the terminal ratings. Refer to
the label on the RM7898 or to the terminal ratings in
Table 3.

Final Wiring Check

1. Check the power supply circuit. The voltage and
frequency tolerance must match those of the RM7898.
A separate power supply circuit can be required for the
RM7898. Add the required disconnect means and
overload protection.
2. Check all wiring circuits and complete Static
Checkout in Table 6 on page 12 before installing the
RM7898 on the subbase.
3. Install all electrical connectors.
4. Restore power to the panel.
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