A
G-TRAC2
IOM-25
23 of 42
Mar 99 R7
BMS Reset from Voltage Applied to + and –
Reset Voltage
(VDC)
Calculated Set-Point
ºC
ºF
0
13
55
4
13.5
56
5
14.5
58
6
16
61
7
18
65
8
20
68
9
23
75
10
26
79
Approximate relationship between 0-10 VDC and 4-20 ma signals is:
VDC
ma
0
0
Note:
zero reset less than 2 VDC or less than 1 ma
2
3
4
8
5
10
6
12
8
16
10
20
BMS Calibration
1.
Apply 20 ma or 10 VDC signal to the G-TRAC2 ‘+ and
’ terminals.
2.
Record the settings of dipswitches 1, 2, and 3.
3.
Measure the G-TRAC2 calculated set point.
(DC voltage across SPC and common readout points in the large cutout hole.
Detail in Section XVII.)
4.
Turn dip switch 1 on.
5.
Measure the new G-TRAC2 calculated set point DC voltage again and adjust the BMS Reset pot until the voltage is equal
to the number of ºC maximum reset desired.
6.
Return the dip switches to their normal position.
Ambient Reset (Day mode only – requires dipswitch A-2 to be on)
This option requires an ambient sensor
(Johnson TE 6000-960)
wired to terminals X and Z. The discharge air set point will
change based on the ambient temperature. As ambient temperatures fall, the discharge temperature will gradually increase
the calculated discharge air set point. The amount of reset is dependent on the position of pot 5 and the manual discharge
air set point. In most cases when the outside ambient is above 70ºF, the heat will be off.
It is possible to obtain an extended temperature range by placing a 120-ohm resistor in series with the ambient
temperature sensor.
