A
G-TRAC2
IOM-25
28 of 42
Mar 99 R7
GTRAC-2 0 – 10 VDC Control
To prevent false lockouts from the low limit or open temperature sensors, the G-TRAC2 must have a temperature sensor or
a jumper must be placed across the G-TRAC2 terminals Q and U. The G-TRAC2 will receive its control signal from the C-
TRAC or Metasys control.
Refer to Section VII dipswitch block C for information on dipswitch set up and Section VIII for pot settings. When C-TRAC2.1
or Metasys is directly controlling G-TRAC2, the low limit safety is normally provided externally to G-TRAC2 as the supply fan
would be controlled by other controls,
(If a discharge sensor were wired to “Q” and “U” of the G-TRAC, it could function and
lock the G-TRAC2 off)
.
1.
Wire the 10 VDC input to the + and – terminals of the G-TRAC2.
2.
Turn on dipswitch A-1
(BR)
. Make sure that switches 2
(amb)
and 3
(RR)
of block A are off.
3.
Connect a DC voltmeter between terminals OR and Z.
4.
Adjust “BMS Reset” pot until the voltage reads between 6.5 and 7.5 volts.
5.
Restore Block 1 switches to their initial positions.
When using a C-TRAC
Set C-TRAC cooling deadband pot 3 to 4 degrees higher than normal value.
Set C-TRAC heat envelope pot to position 1.5
(pot 11)
Heat may stay on due to G-TRAC2 integral timing, if the G-TRAC2 heat switch is left on when the C-TRAC switches to
mechanical cooling. Stage 1 mechanical cooling call should turn power off to the G-TRAC2 terminal “HS” by opening
relay contacts.
XIX. CALCULATED SET-POINT READOUT
(
BASE PLUS CALCULATED
)
NOTE
:
If the unit is operating in night function (terminal K powered) or using the discharge override terminal
(OR), this method will not indicate the correct current operating set point.
The operating discharge set point
(calculated set point)
can be determined by reading the DC voltage across terminals “SPC”
to “common”. The operating set point in ºC is the voltage reading x 10.
(Example: A reading of 2.15 volts = 21.5°C).
To
determine the base
(DIAL)
set point, disable all the set point resets by turning off dipswitches 1, 2, and 3.
To determine calculated set point in °F, determine °C reading then multiply (°C x 1.8) + 32.
Содержание EngA G-TRAC2
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