A
G-TRAC2
IOM-25
37 of 42
Mar 99 R7
Inlet/Manifold Pressure Settings
Manifold pressure settings that the unit was tested and clocked at in the factory are recorded on the unit rating plate. Any
attempt to clock a unit in the field should be done with care. Corrections for density
(altitude and station pressure)
,
temperature, and the correction factor for the meter are often overlooked, thus leading to an incorrect conclusion.
Inlet gas pressures are recorded on the unit label. At high fire inlet gas pressure to the unit should not fall below 6.25" on
units designed for 7" inlet pressure. If design is for 14" pressures should not fall below 12" and should not rise above 14” on
7” inlet and above 18” on 14” inlet.
If design is for 11" propane gas, then inlet pressures should not fall below 10". Note that with propane fired units it may be
necessary to equip the propane system with a properly sized vaporizer. Should not rise above 16” on high fire on 11” inlet.
XIV. SPECIAL SERVICE NOTES
On Board Fuse
The G-TRAC2 is equipped with a 2-amp fuse. This fuse is located on the bottom of the main board and is accessed from
behind the board. If there is 24 VAC to terminals T1 and T2 and the DC voltage from terminals PH to PL is 0 VDC, check the
fuse.
(10.0 to 11.0 VDC is normal if fuse is okay.)
Low Limit Lockouts
NOTE:
If your application does not require it, the Low Limit could be disabled (dipswitch C-5). If there is an
intermittent problem with the discharge sensor, a false low limit lock out code may be generated. This
happens if the discharge sensor generated an initial lockout and then the reason for the sensor lock out
disappeared. (Refer to Section X for more detail on the low limit.)
To reset, remove power from FS and HS simultaneously and resume power to them
(or turn off main power).
If the discharge sensor calibration is not correct, you can also have low limit lockouts.
Be aware if the heat call light comes on, the burner lights, and there is still not enough heat to allow the discharge
temperature to rise above the 40ºF - low limit setting for the period of time that the low limit is being bypassed. The low
limit light will come on when the unit locks off. If the low limit sensor then warms up, both the heat call and low limit light
should remain on until someone resets it by turning the power off to the G-TRAC2.
We strongly recommend that no one
reset the control until the status of all of the troubleshooting lights is recorded.
Failed Operation or Solid State Control Contacts by Others
There have been a number of new controls introduced into the marketplace recently. These allow a building to be
controlled by a central computer
(BMS or Building Management System)
. Many of these devices use relays to switch
external power devices on and off and their operation is fine. However, some of the new
-
-
(open)
position to cause the G-
TRAC2 to malfunction. Voltage leaks of 4 to 5 VAC are common. Only dry contacts should be tied to the G-TRAC2 terminals
unless instructed to do otherwise.
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