Vulcan-Hart SG66 Gas Heater User Manual


 
d) No ignition light (red) comes
ON, module performs a self
diagnostic test for 4 seconds,
2nd valve (main) on the gas
valve is energized. Gas
starts to flow to the burner,
sparking begins, the "no
ignition" light goes out and
burner lights. Sparking
continues for up to 7 seconds
or until a flame is
established. If a flame is
"sensed", the "no ignition"
light stays out and burner
remains lit. If a flame is not
"sensed" after 7 seconds of
sparking, the "no ignition"
light comes back on, 2nd
valve (main) on the gas valve
is de-energize and gas flow
to the burner stops. Ignition
trial cycle repeats after a 15
second purge between
cycles for two additional tries
before locking out. To reset
after a lockout, turn power
switch (S1) OFF then ON.
4. Oven reaches set temperature.
A. Temperature control de-energizes internal
relay and the normally open (N.O.) contacts
OPEN.
1) Heat light goes out.
2) Power removed from heat relay (R3).
a. R3 normally open (N.O.) contacts
OPEN.
a) Power removed from 2nd
valve (main) on the gas valve
and gas flow to the burner
stops.
5. The oven will continue to cycle on the
temperature control until the doors are opened or
power switch (S1) is turned to the OFF or COOL
DOWN position.
Cool Down Cycle (Solid State Temperature
Control)
1. Conditions.
A. Oven is ON.
B. Oven cavity temperature needs to be
lowered.
C. Doors are open.
1) Door switch contacts OPEN
D. Cook timer in the OFF position.
2. Power Switch (S1) turned to COOL DOWN.
NOTE: With door switch contacts OPEN (doors
open), the convection fan motor will still run and
continue to cool the oven. However, power would be
removed from the following components: Power ON
light (goes out), transformer T1 (de-energized) and to
the component cooling fan.
A. Power to motor speed switch (Hi/Low).
1) Motor speed (Hi/Low) relay (R1) is
energized and contacts change state.
a. Convection fan motor energized.
b. When Convection fan motor
reaches operating speed the
centrifugal switch on the motor
closes but no power is available
for connection to other
components.
3. If door switch is CLOSED (doors closed), power
is supplied to one side of the following
components: Power ON light (Amber), oven light
switch (S2), timer terminal 1, transformer primary
(T1) and component cooling fan.
A. Power ON light (Amber) comes ON.
B. Transformer (T1) energized.
1) Power (24VAC) to one side of the
following components: heat relay (R3)
normally open (N.O.) contacts, high
limit --- connected through the normally
closed (N.C.) contacts to the 1st valve
(safety) on the dual solenoid gas valve.
a. 1st valve (safety) on the gas valve
energized.
NOTE: Gas does not flow to the burner until the 2nd
valve (main) is energized.
4. The oven will remain in this condition until the
power switch (S1) is turned to the OFF or ON
position.
SG SERIES GAS CONVECTION OVENS - ELECTRICAL OPERATION
F45525 Rev. A (0315) Page 30 of 33