Honeywell 7800 Series Manual page 13

Fig. 8—RM7888A wiring diagram.
L2
L1
(HOT) MASTER
SWITCH
1
M9495
4. Recommended wire size and type:
a. 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 in-
stallations, use wire selected for a temperature rating
above the maximum operating temperature. All lead-
wires must be moisture resistant.
b. Keyboard Display Module—For communications
purposes, use an unshielded 3-wire twisted cable if
the leadwire run and noise conditions permit; how-
ever, some installations may need up to five wires;
three for communications and two for remote reset
(either in a single cable or separate cables for com-
munications or remote reset) or use Belden 8771
shielded cable or equivalent. The Keyboard Display
Module, DATA CONTROLBUS MODULE™ (for
remote mounting or communications) or Communi-
cations Interface ControlBus Module must be wired in
a daisy-chain configuration, 1(a)-1(a), 2(b)-2(b), 3(c)-
120V ALARM
LIMITS
AIR VALVE
PILOT
MAIN FUEL
VALVE(S)
IGNITION
FLAME
DETECTOR
1 120V POWER SUPPLY. PROVIDE DISCONNECT MEANS
AND OVERLOAD PROTECTION AS REQUIRED.
13
SERIES 90
FIRING
RATE
Q7800 SUBBASE
MOTOR
HIGH
FIRE
G 12
B
COMMON
L2 13 R
LOW
FIRE
3 14 W
MODULATE
4 15
(L1)
SPECIAL
FUNCTION 1
5
16
SPECIAL
FUNCTION 2
6 17
LOW FIRE
7
18
SWITCH
SPECIAL
FUNCTION 3
8
19
SPECIAL
FUNCTION 4
9 20
10 21
FLAME
INDICATION
F
22
FOR DIRECT SPARK
IGNITION (OIL OR GAS)
L2
1ST STAGE
FUEL VALVE
L1
L2
2ND STAGE
FUEL VALVE
IGNITION
3(c)). The order of interconnection of all the devices
is not important. Be aware that modules on the clos-
est and farthest end of the daisy chain configuration
require a 120-ohm (1/4 watt minimum) resistor ter-
mination across terminals 1 and 2 of the electrical
connectors for connections over 100 feet [30 meters],
see Figs. 10, 11 and 12.
c. DATA CONTROLBUS MODULE™—For commu-
nications purposes, use an unshielded 3-wire twisted
cable if the leadwire run and noise conditions permit;
however, some installations may need up to five
wires; three for communications and two for remote
rest (either in a single cable or separate cables for com-
munications or remote reset) or use Belden 8771
shielded cable or equivalent. The Keyboard Display
Module, DATA CONTROLBUS MODULE™ (for
remote mounting or communications) or Communi-
cations Interface ControlBus Module must be wired
in a daisy-chain configuration, 1(a)-1(a), 2(b)-2(b),
SERIES 90
CON-
TROLLER
B
R
W
EXTERNAL
CONTROLLER
8
9
10
65-0175
RM7888A
WIRING