EC7840L1014 Relay Modules
with Valve Proving
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
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
The following assumptions apply when using the RM7840G,L,
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).
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
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.
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.