A
G-TRAC2
IOM-25
35 of 42
Mar 99 R7
4.
High Fire Gas and Air
A.
Place the unit into the service mode
(dipswitch A-5 on)
and power up the G-TRAC2 terminals “T1 and T2” and the
air/gas operators.
B.
(Initial Operator Wiring Pre-Check)
With power to the FS terminal "off", but power to the actuators "on":
Jumper “OG to G”
(open gas)
– the gas actuator should move towards open. The DC volts across terminals PG
to PL should be increasing as the operator moves.
Jumper “CG and G”
(close gas)
– the gas actuator should move back to the closed position.
(Only if required,
interchanging wires “OG and CG” can reverse the above rotation.)
Jumper “OA to A”
(open air)
– the operator should return to the open position. As the operator moves the DC
volts across PA, and PL should be increasing.
Jumper “CA to A”
(close air)
– the air operator should begin to close.
C.
Power the “FS” terminal. Set the manual
service pot
to high fire – full clockwise
(CW)
. Set the “high air” pot to
maximum. Set the low fire and low air pots to mid position.
If the combustion air switch is open and there is a valid discharge sensor, the combustion air blower will start.
This will close the combustion air switch.
If required, the combustion air damper will open to the purge position and the G-TRAC will start the pre-purge
cycle
(85 seconds)
.
Once pre-purge is done both operators will move to the light off position. Once both operators are at the
correct position the flame relay will be energized. In the service mode the G-TRAC will not lock out on flame
failure.
D.
After the flame starts the unit will go to high fire. Adjust the unit gas pressure regulator to obtain the correct
clocked high fire rate. This has been factory pre-set and should not require field adjustment.
E.
Adjust the
high fire air pot
until the high fire O
2
reading is between 3.5 and 4.2%. The
high fire air pot
controls the
opening of the air damper motor by changing the voltage to it. When combustion is set use a 0-10 VAC meter to
measure the air damper position voltage across terminals PA (+) and PL. Record the DC voltage reading.
5.
Low Fire Gas Flow Rate
PG
(hot)
to PL
(neutral)
At the factory, the low fire gas flow rate was clocked. As the manifold pressures are too low to measure in the field,
check low fire gas flow by the following:
Set the manual
service pot
to low fire
(full CCW)
. After both operators have stopped moving, check that the PG to PL DC
voltage matches the low fire data recorded on the G-TRAC2 configuration label.
(Use the low fire pot, only if adjustment
is needed. To make a partial (small) step, rotate the low fire pot the desired direction a very small amount. The control
will not have moved if you are making a very small step, however if you now rotate the
service pot
CW for 3-4 seconds,
then return it to low fire CCW, the gas operator should have stopped at a slightly different position)
6.
Low Fire Combustion Air
PA
(hot)
to PL
(neutral)
Adjust the
low fire air pot
to trim
(set)
the correct low fire oxygen content.
(Eng. Air HT burner = [15.5 to 18.0% for field
set up] 15-18% factory set up.)
Содержание EngA G-TRAC2
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