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EC7820A 7800 SERIES RELAY MODULES
AL
FAN
RT
LD2
PV1
MV
IGN
8
FLAME
DETECTOR
EC7820A Atmospheric + Fan Relay Module with Option for Modulation
LED
DISPLAY
INITIATE
POWER
POWER
PILOT
FLAME
MAIN
ALARM
BURNER
OPERATING
CONTROLS
AND
INTERLOCKS
FLAME
SIGNAL
FREE
NO
FOR
MODULATION
2 sec
OPTIONS
NOTE: IGNITION ATTEMPTS: 1 OR 3
FOR 3: IF NO FLAME, RECYCLE TO WAITING PERIOD; LOCK OUT AFTER 3 TRIES.
1 IF ON AT CALL FOR HEAT, HOLD (120 sec).
LOCK OUT IF STILL ON.
2
IF OFF AFTER 10 SEC OF FAN, LOCK OUT.
3
TAKE LOCKOUT ACTION, CONTINUE 15 SEC
POSTPURGE TIMING
4
SELECT VIA ST7800A PURGE TIMER CARD
5
SELECT VIA CONFIGURATION JUMPERS OR MODEL NUMBERS
Fig. 2. Wiring subbase and operation sequence for EC7820A Relay Module.
66-1091—08
Q7800
G
12
COMMON
N
13
MODULATE
3
14
4
15
(L1)
5
16
6
17
ES2
7
18
ES1
8
19
9
20
LOS
21
10
PV2
F
22
"PREPURGE"
PRE
STANDBY
WAITING
IGNITION
POWER
POWER
POWER
IGNITION
PREIGNITION INTERLOCK
LIMITS AND BURNER CONTROL CLOSED
LOCKOUT INPUT
2
1
10 sec
AFS CHK
SAFE START CHECK
RETRY
COUNT < - 0
6
4
3 sec
AFS CHK
FIRING RATE
CONTROLLER
MOTOR
B
B
R
R
W
W
7
L1
N
FIRST
MAIN TRIAL
PILOT
SAFETY TIME
STABIL.
TIME
POWER
POWER
POWER
PILOT
PILOT
PILOT
FLAME
FLAME
FLAME
MAIN
BURNER/BLOWER MOTOR
PILOT VALVE
V2
AIRFLOW SWITCH CLOSED
LF SWITCH
FLAME PROVING
5
IGNITION ATTEMPTS
5
5
5 or 10 sec
5 sec
5 or 8 sec
6
DUE TO 1 EXTRA SECOND FOR SAFETY RELAY TEST,
TIMING WILL VARY FROM 3 TO 4 SECONDS.
7
220/230/240 VAC, 50/60 Hz POWER SUPPLY.
8
WHEN USING A C7061A OR C7076A,D SENSOR, A 220/240 VAC TO 120 VAC, 10 VA
STEP-DOWNTRANSFORMER MUST BE INSTALLED TO DRIVE THE SHUTTER.
REFER TO AMPLIFIER AND FLAME DETECTOR SPECIFICATIONS FOR
WIRING DETAILS.
8
LEGEND
AL
ALARM
(NORMALLY OPEN)
LOW FIRE SWITCH
ES1
INPUT
PREIGNITION
ES2
INTERLOCK INPUT
BURNER/BLOWER
FAN
MOTOR
IGNITION
IGN
LINE VOLTAGE SUPPLY
L1
LOCKOUT INPUT
LOS
AIRFLOW SWITCH INPUT
LD2
MAIN FUEL VALVE
MV
PILOT VALVE 1
PV1
(INTERRUPTED)
PILOT VALVE 2
PV2
(INTERMITTENT)
LIMITS AND BURNER
RT
CONTROL
MAIN
STABIL.
RUN
STANDBY
POWER
POWER
POWER
PILOT
PILOT
FLAME
FLAME
MAIN
MAIN
MAIN VALVE
5 sec
AFS CHK
SSC
RETRY
COUNT < - 0
YES
5 sec
M11630B
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