INSTALLATION INSTRUCTIONS
66-1162-2
RM7800L1087; RM7840G1022,L1075;
EC7840L1014 Relay Modules
with Valve Proving
APPLICATION
The Honeywell RM7800L/40L and EC7840L Relay Modules
are microprocessor-based integrated burner controls for
automatically fired gas, oil, or combination fuel single burner
applications. The RM7800L/40L and EC7840L Relay Modules
are used for UL/CSA Modulating and FM/IRI Modulating
burner applications. The RM7800L/40L, EC7840L system
consists of a Relay Module. Keyboard Display Modules
(standard with RM7800), Dust Cover (standard with RM7840/
EC7840L), Subbase, Amplifier, and Purge Card. Options
include Personal Computer Interface, DATA CONTROLBUS
MODULE™, Remote Display Mounting, First-Out Expanded
Annunciator and Combustion System Manager™ Software.
Functions provided by the RM7800L/40L, EC7840L include
automatic burner sequencing, flame supervision, system
status indication, system or self-diagnostics and
troubleshooting.
RM7800L1087/RM7840G1022,L1075; EC7840L1014 offer
the Valve Proving test feature.
Using the S7800A1142 Keyboard Display (standard on
RM7800L1087) the following features can be set up:
• Post Purge time—Up to 66 minutes—Device shipped
with 15 seconds Post purge.
• Valve Proving features including:
— VPS test time
— When (Never, Before, After, Split or Both)
See S7800A1142 Instructions (65-0288) for its features.
Series 5 can be programmed for Modbus communication.
At commissioning time, the Valve Proving System may be
scheduled to occur at one of five different times:
• Never—Device default as received—Valve proving
does not occur.
• Before—Valve proving before run concurrent with Pre-Purge.
• After—Valve proving occurs after the Run state, before
the device goes to Standby (Concurrent with Post-
Purge, if selected.)
• Both—Valve proving occurs at both times Before and
After, noted above.
• Split—The main valve 2 (MV2) (high pressure) seat test
is performed at the Before time and the main valve 1
(MV1) (low pressure) seat test is performed during the
After time.
The following assumptions apply when using the RM7840G,L,
RM7800L, EC7840L:
Fig. 1. The valve proving system.
MV1—Wired to terminal 9. It is located in the most upstream
position of the main gas valve train.
VPS—Valve Proving Switch: Setpoint at 1/2 of Main Valve
inlet pressure.
MV2—Wired to terminal 21. It is the main valve located
closest to the burner.
The PII—Pre-Ignition Interlock (or Proof of Closure Switch) for
terminal 20 can be installed on MV1, MV2, or as a series
connection through both valves.
Appendix B lists many wiring options for single and dual fuel
along with the Valve Proving options.
SPECIFICATIONS
Electrical Ratings, see Table 3:
Voltage and Frequency:
RM78xx—120 Vac (+10/-15%), 50 or 60 Hz (±10%).
EC78xx—220–240 Vac (+10/-15%), 50 or 60 Hz (±10%).
Power Dissipation: RM7800/RM7840/EC7840L: 10W
maximum in the Run mode.
MV1
MV2
VP
SW.
M24161
OUTLET
INLET
1 CAUTION: VALVE ENERGIZING TIMING IS BASED ON HONEYWELL VALVE
OPENING TIMES OF 13 SECONDS MAXIMUM.
− FOR VALVES WITH TIMINGS GREATER THAN 13
SECONDS OR THOSE THAT DO NOT OPEN THE ACTIVE
VALVE WITHIN THE ENERGIZED TIME, A BYPASS
SOLENOID VALVE (1/4”, 120 VAC) IS REQUIRED TO
OBTAIN THE PROPER TEST PRESSURES.
− THE BYPASS VALVE WILL BE WIRED IN PARALLEL TO THE
VALVE IT IS BYPASSING (TERMINAL 9 FOR MV1 OR
TERMINAL 21 FOR MV2).
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