7800 SERIES RM7824A RELAY MODULE
65-0155—1
7
WIRING
1. a. For the internal block diagram of the RM7824A,
see Fig. 5.
b. For proper subbase wiring, refer to Fig. 6.
c. For proper remote wiring of the Keyboard Display
Module; refer to the Specifications for the
Keyboard Display Module (65-0090),
Communication Interface Base Unit (63-2278),
DATA CONTROLBUS MODULE™ (65-0091), or
Extension Cable Assembly (65-0131).
2. Disconnect the power supply from the main disconnect
before beginning installation to prevent electrical shock
and equipment damage. More than one disconnect may
be involved.
3. All wiring must comply with all appropriate electrical
codes, ordinances and regulations. Wiring, where
required, must comply with NEC Class 1 wiring.
4. a. Recommended wire size and type: Use No. 14, 16,
or 18 copper conductor (TTW60C or THW75C or
THHN90C) 600 volt insulation wire for all low
voltage terminals. For high temperature
installations, use wire selected for a temperature
rating above the maximum operating temperature.
All leadwires must be moisture resistant.
b. The maximum number of wires per terminal is
two. If more than two wires need to be connected
to a terminal, wire one of the wires to the terminal
and use a wire nut to connect the other wires
inside the subbase.
5. Recommended wire routing for flame detector
leadwires:
• Do not run high voltage ignition transformer wires
in the same conduit with the flame detection
wiring.
• Do not route scanner wires in a conduit with line
voltage circuits.
• Enclose scanner wires without armor cable in
metal cable or conduit.
•Follow directions given in the flame detector
instructions.
6. Maximum wire lengths:
a. For the RM7824A, the maximum length of
leadwire to the control terminal input is 300 feet.
b. For the flame detector leadwires, the maximum
flame sensor leadwire length is limited by the
flame signal strength.
Fig. 5. Internal block diagram of the RM7824A (see Fig. 6 for detailed wiring instructions).
CONFIGURATION
JUMPERS
MICROCOMPUTER
RESET
PUSHBUTTON
STATUS LEDs
SAFETY RELAY
CIRCUIT
POWER SUPPLY
OPTIONAL KEYBOARD
DISPLAY MODULE
PLUG-IN
FLAME
AMPLIFIER
RELAY
DRIVE
CIRCUIT
CONTROL
POWER
TEST
JACK
REMOTE
RESET
DDL
DDL
COMMUNICATIONS
INDICATES FEEDBACK SENSING
TO RELAY STATUS FEEDBACK
AND LINE VOLT INPUTS
FIELD WIRING
INTERNAL WIRING
IGNITION
PILOT
MAIN VALVE
1K
RELAY
STATUS
FEEDBACK
AND LINE
VOLTAGE
INPUTS
LIMITS CONTROLLER
1K1 2K1
24 VDC
FLAME SIGNAL
TEST
PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
RS485
1
2
3
+–
3
6
2K2
10
8
9
4K
3K
2K
F
G
22
1
ALARM
3K1
4
L2
1
M5821
4K1