A G-TRAC2
IOM-25 8 of 42 Mar 99 R7
VI. SYSTEM TIMINGS
75 seconds at 85% opening
Supply fan start delay (damper open time)
Heat exchanger warm up time
Heat exchanger cool down time
1 min (except on low limit failure)
Usually 15 seconds (it is set by flame relay)
90 seconds from ignition command
Auto Low limit Bypass (from blower start)
5 minutes 30 second anti-cycle timer
VII. BLOWER AIR AND GAS MODULATION
As a gas valve or damper opens or closes, the flow through the device changes in a non-linear fashion. This varying flow rate
normally creates set up and operating problems. Advanced technology in the G-TRAC2 corrects these issues.
The G-TRAC2 monitors both the gas and air operator positions and calculates the corrected flow rates. Modulating
adjustments of the gas and air are based on flow rates through gas valves and dampers, not on degrees of control rotation
that other systems use. This allows the G-TRAC2 to maintain an accurate set up throughout the complete combustion
range.
Refer to Section XXII for set-up procedures and Section XXIII for information changing operators or G-TRAC2’s in the field.
VIII. DIP SWITCHES
The G-TRAC2 has three dip switch blocks (each block has 5 switches). The individual switches are numbered from 1 through
5 and are used for the following purposes:
Dip Switch Block A
Is accessible from the large opening on the G-TRAC label. Switch 1 of Block A is located on the right hand side. The switches
are used to activate the following functions:
A-1 BMS reset (0-10 VDC, 0-10 VDC, 4-20 ma).
A-2 Ambient reset.
A-3 Room reset.
A-4 Supply Fan configuration switch. (At start-up and during operation "ON" maintains airflow as a priority, to
pressurize space. "OFF” the discharge temperature has priority).
NOTE: If the airflow has priority then the supply fan doesn’t shut down if the discharge temperature is too cold.
(Often selected as per day/night configuration chart.) This statement applies to the GTRAC-2 control
starting up from a cold start.
A-5 Service mode - If this switch is ‘on’ the ‘Heat Required’ light will be flashing, erratically, indicating the control is in a
service mode.