7800 SERIES EC7885A/RM7885A RELAY MODULE
65-0203
16
b.
Ground the earth ground terminal for each 7885A
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:
1.
Do not run high voltage ignition transformer wires
in the same conduit with the flame detection
wiring.
2.
Do not route scanner wires in a conduit with line
voltage circuits.
3.
Enclose scanner wires without armor cable in
metal cable or conduit.
4.
Follow directions given in the flame detector
Instructions.
7. Maximum wire lengths:
a.
For the 7885A, the maximum length of leadwire
to the terminal inputs (Control) is 300 feet.
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 7885A or to the ratings of the
applicable Specification, see Table 1.
9. Check the power supply circuit. The voltage and
frequency tolerance must match those of the 7885A.
Do not connect the 7885A to a power supply circuit that
can have line voltage variations such as on-off
switching of heavy loads. A separate power supply
circuit may be required for the 7885A with the required
disconnect means and overload protection added.
10. Check all wiring circuits and complete Static Checkout,
Table 4, before installing the 7885A on the subbase.
11. Install all electrical connectors.
12. Restore power to the panel.
ASSEMBLY
Mounting 7885A
NOTE:
For installation dimensions, see Fig. 1 or 2.
Relay Module Mounting
1. Mount the 7885A vertically, see Fig. 12 or 13, or mount
horizontally with the knife blade terminals pointing
downward. When mounted on the Q7800A, the 7885A
must be in an electrical enclosure.
2. Select the location in the electrical enclosure. Be sure
to allow adequate clearance for servicing, installation
and removal of the 7885A, Dust Cover, flame amplifier,
flame amplifier signal voltage probes, electrical signal
voltage probes and electrical connections.
a.
Allow an additional two inches below the 7885A
for the flame amplifier mounting.
b.
Allow an optional three inches minimum to both
sides of the 7885A for electrical signal voltage
probes.
3. Make sure no subbase wiring is projecting beyond the
terminal blocks. Tuck in wiring against the back of the
subbase so it does not interfere with the knife blade
terminals or bifurcated contacts.
4. Mount the 7885A by aligning the four L shaped corner
guides and knife blade terminals with the bifurcated
contacts on the wiring subbase and securely tightening
the two screws without deforming the plastic.
IMPORTANT
Install the 7885A with a plug-in action rather than a
hinge action.
Fig. 12. Electrical panel installation.
