RELAY MODULES WITH VALVE PROVING
32-00142—01 20
Ignition Trials—Valve Proving with DSI
System
1. Demand connected to Terminal 17:
— JR2 Intact on RM7800L/40L, EC7840L
— JR3 Intact on RM7840G
a. Ignition, Main Valve 1 and Main Valve 2, Termi-
nals 10, 9, and 21 turn on together.
b. Flame must be proven at the end of the 4 second
Main Flame Establishing Time.
c. Ignition, Terminal 10 is turned off. System now in
Run.
d. If Flame is not proven, safety lockout occurs.
Run
1. A ten-second stabilization period occurs at the
beginning of the RUN period.
2. The firing rate motor releases to modulation.
3. The RM7800L/40G,L, EC7840L is now in RUN and
remains in RUN until the controller input, terminal 6,
opens (terminal 17, on VP applications), indicating
that the demand is satisfied or a limit opened.
Postpurge
The RM7800L/40G,L, EC7840L provides a programmable
(default is 15 seconds) POSTPURGE following the
completion of the RUN period. The blower motor output is
powered to drive all products of combustion and any
unburned fuel from the combustion chamber. It also
supplies combustion air to burn fuel being purged from
the fuel line downstream of the fuel shutoff valve.
1. The main fuel valve and intermittent pilot valve,
Terminals 9 and 21, are de-energized and the firing
rate motor is commanded to the low fire position to
begin the POSTPURGE period.
2. The Pre-Ignition Interlock closes within the first five
seconds after the demand opens.
3. If Valve Proving option—After, Split or Both have
been selected, then the Valve Proving test will be
conducted concurrent with Postpurge. If Postpurge
timing remains after the Valve Proving test is com-
pleted, the Postpurge timing will complete before
the RM7800/40G,L, EC7840L go into standby.
Table 7. Sequence Timing for Normal Operation.
* STANDBY and RUN can be an infinite time period.
**PURGE determined by which ST7800A purge card is selected.
a
The MFEP is determined by which terminal is used, configuration jumper selected or jumper wire added.
See Fig. 2, 3, 4, 6, and 7.
b
If DSI is Enabled on a VP application (JR2 intact on RM7800L/40L, EC7840L or JR3 intact on RM7800/40G) then Igni-
tion (terminal 10) and MV
1
(terminal 9), and MV
2
(terminal 21) are energized together. After 4 seconds terminal 10 shuts
off, and system goes to Run.
c
If DSI is disabled on a VP application then MFEP is 10 seconds.
d
Default is 15 seconds. Can be programmed as long as 66 minutes.
Device Initiate Standby Purge
Flame Establishing Period
Run
Post-
Purge
Timing
d
Interlock Circuits
Firing Rate
Circuit
Approval
Code BodiesPilot Main
a, c
RM7840G 10 sec. * ** 4 or 10 sec. 10, 15 sec. or
intermittent
b
* 15 sec. Pre-Ignition, Running,
Low Fire
4-wire
modulating
UL/CSA
Modulating
RM7800L/R
M7840L/
EC7840L
10 or 15 sec.
b
Pre-Ignition, Lockout,
High and Low Fire
FM/IRI
Modulating
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