Honeywell 7800 Series Installation Manual page 5

3
RESET
PUSH-
BUTTON
STATUS LED
3K1
OPTIONAL KEYBOARD
DISPLAY MODULE
DDL
1
DDL
COMMUNICATIONS
M5133D
Fig. 2. Internal block diagram of RM7885A (see Fig. 2 through 6 for detailed wiring instructions).
Application
Line voltage terminals
Keyboard Display Module 22 AWG two-wire twisted pair with ground, or
Data ControlBus Module™ 22 AWG two-wire twisted pair with ground, or
Remote Reset Module
Communication Interface
ControlBus™ Module
13 Vdc full-wave rectified
transformer power input
The Keyboard Display Module, Data ControlBus Module™
(for remote mounting or communications) or
Communication Interface ControlBus Module must be
wired in a daisy chain configuration, (1(a)-1(a), 2(b)-2(b),
3(c)-3(c)). The order of interconnection of all the devices
listed above is not important. Be aware that modules on
the closest and farthest end of the daisy chain
configuration string require a 120 ohm (1/4 watt
minimum) resistor termination across terminals 1 and 2 of
the electrical connectors for connections over 100 feet (31
meters).
L1
L2
(HOT)
1 2
MICROCOMPUTER
2K
RELAY
DRIVE 3K
CIRCUIT
4K
5K
SAFETY RELAY
1K POWER SUPPLY
CIRCUIT
1K1
6
LIMITS
INDICATES FEEDBACK SENSING
TO RELAY STATUS FEEDBACK
AND LINE VOLT INPUTS
RS485
FIELD WIRING
INTERNAL WIRING
2
3
REMOTE
RESET
1 PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2 RM7885: 120 VAC, 50/60 HZ; EC7885A: 220-240 VAC, 50/60 HZ.
EC7885A RELAY MODULE REQUIRES A 220/240 VAC TO 120 VAC, 10 VA, STEPDOWN
3
TRANSFORMER (NOT SUPPLIED) TO DRIVE THE SHUTTER ON C7012E,F,
C7061A AND C7076A,D FLAME DETECTORS.
Table 1. Recommended Wire Sizes and Part Numbers.
Recommended Wire Size
14, 16, or 18 AWG copper conductor, 600 volt
insulation, moisture-resistant wire.
five-wire.
five-wire.
22 AWG two-wire twisted pair, insulated for
low voltage.
22 AWG two-wire twisted pair with ground.
18 AWG wire insulated for voltages and
temperatures for given application.
TEST
FLAME SIGNAL
JACK
F
PLUG-IN
G
FLAME
TEST
AMPLIFIER
22
CONTROL
4K1
POWER
2K2
TTW60C, THW75C, THHN90C.
Belden 8723 shielded cable or equivalent.
Belden 8723 shielded cable or equivalent.
—
Belden 8723 shielded cable or equivalent.
TTW60C, THW75C, THHN90C.
5
RM7885A 7800 SERIES RELAY MODULES
3
RELAY
STATUS
FEEDBACK
AND LINE
VOLTAGE
INPUTS
8 PILOT
S445A
START
IGNITION
10 C D
A B
STOP
9 MAIN VALVE(S)
R4155A
4 4
5 6 2
ALARM
Recommended Part Numbers
L2
32-00215—01