Honeywell RM7824A Benutzerhandbuch

7800 SERIES RM7824A RELAY MODULE

65-0155—1

11

CAPTIVE
MOUNTING
SCREW

DUST
COVER

RELAY
MODULE

FLAME
AMPLIFIER

FLAME CURRENT
TEST JACK

FLAME
SIMULATOR INPUT

SEQUENCE
STATUS LEDS

RESET
PUSH-
BUTTON

M7593

The RM7824A enters the INITIATE sequence if the Relay
Module verifies voltage fluctuations of outside 22 to 28 Vdc
during any part of the operating sequence. The INITIATE
sequence lasts for ten seconds unless the voltage tolerance
is not met. When the tolerance is not met, a hold condition will
be initiated and will be displayed on the optional Keyboard
Display Module for at least five seconds. When the tolerance
is met, the INITIATE sequence will restart. If the condition is
not corrected and the hold condition exists for four minutes,
the RM7824A will lock out. Causes for hold conditions in the
INITIATE sequence are:

•

Vdc dropout is detected.

•

Internal timing functions are not synchronized.

•

The noise that can prevent a sufficient reading of the low
voltage inputs.

•

Brownouts caused by low input voltage.

INITIATE

STANDBY

STANDBY 
HOLD:  F/G  
(FLAME
DETECTED)

POWER

PILOT

FLAME

MAIN

POWER

PILOT

FLAME

MAIN

PILOT 
IGNITION

SAFE-
START 
CHECK

ALARM

POWER

FLAME

MAIN

PILOT

ALARM

ALARM

POWER

FLAME

MAIN

PILOT

ALARM

POWER

FLAME

MAIN

PILOT

ALARM

POWER

FLAME

MAIN

PILOT

ALARM

POWER

FLAME

MAIN

PILOT

ALARM

RESET/
ALARM
TEST

RUN

M3362

The RM7824A is ready to start an operating sequence when
the operating control input determines a 

call for heat is present.

The burner switch, limits, operating limit control and all
microcomputer monitored circuits must be in the correct state
for the RM7824A to continue into the SAFE-START CHECK.

The RM7824A verifies that a flame does not exist and
proceeds into the ignition trial. If a flame is present, the
RM7824A will recycle to the STANDBY period. If the critical
loads are not in the correct state, a safety shutdown occurs.

Pilot Flame Establishing Period (PFEP):

1. The pilot valve and ignition transformer, terminals 8 and

10, are energized. The RM7824A has an intermittent
pilot valve, terminal 8.

2. Flame must be proven by the end of the 4 or 10 second

PFEP to allow the sequence to continue. If flame is not
proven by the end of PFEP, a safety shutdown occurs.

3. With flame proven, the ignition, terminal 10, is de-

energized and the main valve, terminal 9, is energized.

The RM7824A is now in RUN and will remain in RUN until the
controller input, terminal 6, opens, indicating that the demand
is satisfied or a limit has opened.

The RM7824A has one site-configurable jumper option, see
Fig. 15 and Table 4. The site-configurable jumper should be
clipped with side cutters and the resistor removed from the
Relay Module.

SELECTABLE CONFIGURATION JUMPER

M7592