Honeywell 7800 SERIES Manual page 10

RM7890A,B,C
INSTALLATION
IMPORTANT:
1. For on-off gas-fired systems, some authorities who
have jurisdiction prohibit the wiring of any limit or
operating contacts in series between the flame safe-
guard control and the main fuel valve(s).
2. Two detectors can be connected in parallel with the
exception of Infrared Detectors (C7015).
3. This equipment generates, uses and can radiate radio
frequency energy and, if not installed and used in
accordance with the instructions, may cause interfer-
ence to radio communications. It has been tested and
found to comply with the limits for a Class B comput-
ing device of part 15 of FCC rules, which are designed
to provide reasonable protection against such inter-
ference when operated in a commercial environment.
Operation of this equipment in a residential area may
cause interference; in which case, the users at their
own expense may be required to take whatever mea-
sures are required to correct this interference.
Fig. 6—Internal block diagram of the RM7890 (see Fig. 7 for detailed wiring instructions).
DDL
COMMUNICATIONS
1
65-0126—2
3
CONFIGURATION
JUMPERS
MICROCOMPUTER
RESET
PUSH-
BUTTON
RELAY
DRIVE
CIRCUIT
SAFETY RELAY
CIRCUIT
STATUS LEDs
LIMITS CONTROLLER
6
3K1
OPTIONAL KEYBOARD
DISPLAY MODULE
DDL
RS485
1
2
3
REMOTE
RESET
PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
4. This digital apparatus does not exceed the Class B
limits for radio noise of digital apparatus set out in the
Radio Interference Regulations of the Canadian De-
partment of Communications.
HUMIDITY
Install the RM7890 where the relative humidity never
reaches the saturation point. The RM7890 is designed to
operate in a maximum 85% RH continuous, noncondensing
moisture environment. Condensing moisture may cause a
safety shutdown.
VIBRATION
Do not install the RM7890 where it could be subjected to
vibration in excess of 0.5G continuous maximum vibration.
WEATHER
The RM7890 is not designed to be weather tight. If
installed outdoors, the RM7890 must be protected by an
approved weather-tight enclosure.
L1
L2
(HOT)
1
120 Vac
FLAME SIGNAL
PLUG-IN
FLAME
AMPLIFIER
TEST
2K
3K
RELAY
4K
STATUS
FEEDBACK
AND LINE
VOLTAGE
INPUTS
1K
CONTROL
POWER SUPPLY
POWER
1K1 4K1 2K1
10
8
2K2
9
4
INDICATES FEEDBACK SENSING
TO RELAY STATUS FEEDBACK
AND LINE VOLT INPUTS
FIELD WIRING
INTERNAL WIRING
10
L2
RM7890C
TEST
JACK
F F
N. O.
G
22
IGNITION
PILOT
MAIN VALVE
ALARM
M9093