Wayne HSG200 Manual - page 11
PAGE 10
SEQUENCE OF OPERATION - HSG SERIES
POWER GAS CONVERSION BURNER UTILIZING
HONEYWELL S89E GAS PRIMARY P/N 62758-002 W/ EXTERNAL
30 SECOND PREPURGE TIMER P/N 62388-001 AND RESISTOR P/N 62530-001
On a call for heat, voltage (24V) is applied to the motor
start relay and air switch. The motor relay pulls in the
motor. After the motor reaches speed, the combustion
air blower closes the air proving switch contacts,
energizing the external 30 second prepurge timer. After
the 30 second prepurge timing, the S89E is energized.
The S89E gas primary control has an internal 8 second
safe start check. After the initial 30 second prepurge
provided by the external timer, the S89E gas primary
control is energized, the 8 second safe start check will
commence. Once this is accomplished, the S89E
activates the gas valve allowing gas to flow to the burner
head. Simultaneously, the S89E control energizes the
ignition transformer, producing an approximate 7300
volt spark end point grounded at the burner head,
establishing main burner flame.
At the start of each heat cycle, there is a trial for ignition
period of four (4) seconds duration. Normally, burner
flame will be established before the end of this period.
Once the flame is established, sparking will cease and
the flame rod will provide flame monitoring to the S89E
gas primary control for the remainder of the heat cycle.
When utilizing the S89E gas primary control with the
eternal 30 second prepurge timer, a 10K ohm resistor is
wired in parallel between the output terminal of the 30
second prepurge timer and the input terminal to the
S89E gas primary control. The function of this resistor
is to keep a load on the output terminal of the external
30 second prepurge timer, after the initial call for heat
and 30 second start prepurge and 8 second safe start
check.
This promotes simultaneous re-ignition of the main
burner flame after the S89E’s 8 second safe start check,
overriding the 30 second prepurge. This is desirable in
oven or similar applications where temperatures cannot
vary drastically.
Should the flame be extinguished during the heat cycle,
the S89E primary ignition control will go into the 8
second safe start check after which time it will re-
energize the gas valve and ignition transformer in an
attempt to re-establish the main burner flame. If this
does not occur within the 4 second trial for ignition
period, the S89E gas primary control will go into lockout
de-energizing the gas valve and ignition transformer. To
restart the system, the main power or thermostat must
be de-energized momentarily, then re-energized. If at
any time during the heat cycle, there is insufficient
supply of combustion air to the burner, the air switch
contacts will open, putting the system into lockout
closing the gas valve.
HSG POWER GAS BURNER
WITH HONEYWELL S89E GAS PRIMARY