Wiring - Honeywell 7800 Series Product Data

S7800A KEYBOARD DISPLAY MODULE OR
S7810A DATA CONTROLBUS MODULE™
(MOUNTED ON 7800 SERIES RELAY MODULE)
1 2 3
Fig. 5. Wiring the S7800B Display Module.

WIRING

1. Refer to Fig. 5 for proper wiring.
2. Disconnect the power supply from the main disconnect
before beginning installation to prevent electrical shock
and equipment and control damage. More than one
disconnect may be involved.
3. Be sure all wiring complies with all applicable electrical
codes, ordinances and regulations.
4. Connect lead wires as follows:
a. Connect the yellow leadwire from the S7800B
Display to terminal 1-A of the S7800A or S7810A
Module.
b. Connect the green leadwire from the S7800B
Display to terminal 2-B of the S7800A or S7810A
Module.
c. Connect the black leadwire from the S7800A
Display to terminal 3-C of the S7800A or S7810A
Module. The negative terminal of the 12 Vdc
power supply must also be connected to the black
leadwire.
d. Connect the red leadwire from the S7800B
Display to the positive terminal of the 12 Vdc
power supply.
If the leadwires must be extended, use no. 22 AWG 600V
rated, twisted-pair wire. For leadwire lengths greater than
100 ft (30m), install 120 ohm, 1/4 watt termination
resistor between terminals 1-A and 2-B of the S7800A or
S7810B Module and the yellow and green leadwires of
the S7800B Display Module. Place these termination
resistors as close as possible to the modules.
NOTE: In extreme electrical noise conditions, the
twisted-pair wire may require substituting
with Belden 8771 shield cable or equivalent.
The shield must be grounded at both ends of
the cable.
MOMENTARY
PUSHBUTTON
SWITCH
4 5
12 VDC CLASS 2
POWER SUPPLY
L1
+
(HOT)
L2
–
RED S7800B
DISPLAY
BLACK
GREEN
YELLOW
M11125
7800 SERIES S7800B DISPLAY MODULE
If more than one Display Module is remote mounted,
wire the module in a daisy chain configuration.
NOTE: If termination resistors are being used, install
resistors only at the devices on the closest and
farthest end of the daisy chain configuration.
e. For remote reset (optional only for S7800A or
S7810A), use no. 22 AWG 600V rated, twisted-pair
wire. Maximum length is 1000 feet (300 meters).
Connect terminals 3-C and 5-Reset of the S7800A
or S7810A Modules to the normally open (N.O.)
contact of a momentary pushbutton switch.
5. Ground the S7800B Display Module using the supplied
grounding lug. Connect the lug to one of the panel
mounting screws or one of the screws that holds the
endplates on the S7800B chassis. Use no. 18 AWG
wire for grounding.
6. Recommended wire routing:
a. ControlBus:
1. Do not route the ControlBus cable in
conduits that carry line voltage circuits.
2. Avoid routing the ControlBus cable close to
ignition transformer leadwires.
3. Route the ControlBus cable outside of
conduit if properly supported and protected
from damage.
b. Remote Reset:
1. Do not run high voltage ignition transformer
wires in the same conduit with the Remote
Reset wiring.
2. Do not route Remote Reset wires on conduit
with the line voltage circuits.
7. Maximum wire lengths:
a. S700A Keyboard Display Module and S7800B
Display Module—The maximum length
interconnecting wire is 4000 feet (1219 meters).
b. Remote Reset Leadwires—The maximum length
wire is 1000 feet (300 meters) to a Remote Reset
pushbutton.
8. Install all electrical connectors.
9. Restore power to the panel.
NOTE: A 12 Vdc power supply must be used any time
more than one Keyboard Display Module is
used.
S7800B Display Module LCD
The first line of the liquid crystal display (LCD) provides
current status of the burner sequence, timing information in
minutes and seconds, hold information (PURGE HOLD) and
lockout information (Lockout, Fault Code, Message and
Sequence), see Fig. 6. The extreme right side of the first line
will be either blank or it will show a small arrow pointing to the
second line followed by a two-letter code (DI=Diagnostic
Information and H1=Fault History Information). When the
arrow and two-letter code are displayed, it indicates the
second line is showing a selectable message submenu. The
second line displays selectable or pre-emptive messages. A
selectable message supplies information for flame strength,
system status indication, system or self-diagnostics and
troubleshooting. A pre-emptive message provides a detailed
message to support the sequence status information. A pre-
emptive message can also be a lockout message. A pre-
emptive message replaces a selectable message to support
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