ACC-SVN190B-EN
15
Figure 15.
Thermistor wires
Thermistor #2
Low Ambient
Controller
Pop-in Wire Tie
Thermistor #1
Low Ambient
Controller
Grommets
To Thermistor #1
To Thermistor #2
Controller Settings
Jumper Position for TTA Models (Cooling
Only)
For non-heat pump applications, the heat pump select
jumper must be in the Default (N.O.) position, and the
HP terminals must be left unconnected. Refer to
.
Figure 16.
Jumper position for TTA
N.C.
C
Y1
REV.
V
A
LVE
P1&
P2
BLK
HEAT
PUMP
N.O.
T
A
MB
IENT
P1&P2 RED
P2 B.W.
G.
P1
B.
W.G.
Y1
Y2
T’S
T
A
T
24 VAC
COMMON
Y2
N.O.
Jumper Position for TWA Models (Heat
Pump)
For heat pump applications, the heat pump select
jumper must be in the (N.C.) position, see
Figure 17.
Jumper position for TWA
N.C.
C
Y1
REV.
V
A
LVE
P1&
P2
BLK
HEAT
PUMP
N.O.
T
A
MB
IENT
P1&P2 RED
P2 B.W.
G.
P1 B
.W.
G.
Y1
Y2
T’STA
T
24 VAC
COMMON
Y2
N.C.
Operation
The low ambient controller is used to maintain head
pressure within an acceptable range when ambient
temperature falls below 50 °F. It reads discharge
pressure from the refrigeration circuit and “cycles” the
outdoor fan motor on and off to maintain the desired
