During Operation - Dunkirk Q90 150 Installation Manual And Operating Instructions

SAFETY SEQUENCES DURING OPERATION
DRAFT INDUCER TEMPERATURE SAFETY SWITCH
IF DRAFT INDUCER TEMPERATURE REACHES i
TEMPERATURE SAFETY SWITCH SETPOINT,
/
SAFETY SWITCH CONTACTS OPEN IMMEDIATELY, I
[ CLOS NG GAS VALVE_ (L GHT GOES OUT). J
[ ]
POST PURGE AND SWITCHES OFF.
FOR_HEAT.
rWHEN TEMPERATURE SAFETY SWITCH CONTACTS
EMAKE BEFORE END OF CALL FOR HEAT, CON- I
[TROL GOES NTO NORMAL L GHT-OFF SEQUENCE.J
LOSS OF FLAME SIGNAL
IF AN ESTABLISHED FLAME SIGNAL IS LOST WHILE
CONTROL EXPECTS THAT THE BURNER IS OPERAT-
ING, CONTROL WILL IMMEDIATELY DE-ENERGIZE
GAS VALVE. VALVE AND FLAME L GHTS GO OUT.
CONTROL WILLATTEMPT TO RELIGHT BOILER
3 TIMES. IF FLAME IS NOT PROVEN, CONTROL
LOCKOUT - PROBLEM ESTABLISHING A FLAME
SIGNAL. VALVE LIGHT IS BLINKING, CONTROL
WILL AUTOMATICALLY RESET AFTER 1 HOUR.
LOSS OF COMBUSTION AIRFLOW
iF COMBUSTION AIRFLOW IS LOST WHILE BURNER
IS FIRING (DIFFERENTIALAIR PRESSURE SWITCH
CONTACTS OPEN) GAS VALVE WILL BE DE-ENER-
G ZED. VALVE AND FLAME L GHTS GO OUT.
[
!
UTES FOR AIRFLOW TO BE RE-ESTABLISHED.
IF AIRFLOW DOES NOT RE-ESTABLISH CON-
TROL LOCKOUT - PROBLEM WITH COMBUSTION
AIRFLOW. PURGE LIGHT BLINKS. CONTROL WILL I
[ AUTOMAT CALLY RESETAFTER 15 M NUTES. J
CASTING TEMPERATURE SAFETY SWITCH
IF BURNER OPERATES WHEN BOILER HAS NO WA- i /
ER, ALUMINUM BOILER SECTIONS HEAT UP RAPIDLY.J
CASTING TEMPERATURE SAFETY SWITCH CON-
TACTS WILL OPEN, BREAKING 24 VOLT POWER
TO IBC. POWER INDICATOR LIGHT GOES OUT.
REQUIRES MANUAL RESET TO RECLOSE CON-
TACTS. POWER LIGHT GOES OUT.
HIGH LIMIT CONTROL
IF BOILER WATER TEMPERATURE REACHES i
HIGH LIMIT (AQUASTAT) SETPOINT, HIGH LIMIT
/
N.C. CONTACTS OPEN IMMEDIATELY, CLOSING
GAS VALVE. VALVE AND FLAME L GHTS GO OUT.J
DRAFT INDUCER CONTINUES TO RUN FOR 30 |
SECOND POST PURGE AND SWITCH OFF.
!
CIRCULATOR RUNS AS LONG AS THERMOSTAT |
CALLS FOR HEAT.
!
WHEN HIGH LIMIT CONTACTS REMAKE BEFORE]
END OF CALL FOR HEAT - CONTROL GOES INTO
A NORMAL L GHT-OFF SEQUENCE. J
CIRCULATOR PUMP
CIRCULATOR WILL BE ENERGIZED AS LONG AS
THERMOSTAT CALLS FOR_HEAT DUR NG LOCKOUT.]
RECOVERY FROM ANY LOCKOUT REQUIRES
RESET, WHICH CAN BE ACCOMPLISHED BY:
(A) REMOVING AND REESTABLISHING THE
THERMOSTATS CALL FOR HEAT OR TURNING
THE SERVICE SWITCH OFF AND BACK ON;
OR (B) WAITING FOR THE CONTROL TO
AUTOMATICALLY RESETAFTER 15 MINUTES
FOR LOSS OF COMBUSTION AIRFLOW OR
ONE HOUR FOR LOSS OF FLAME.