Part 7:
SOLID STATE CIRCUIT BOARDS
7.4.2 Temperature/Pressure Display Board
Refer to Fig. 7.4.2 and the instructions on page 75 and the test point descriptions below.
Temperature/Pressure Display Board Connectors:
CN1 —
10 pin connector accepts the cable from the Timer Control Board.
There are no test points on CN1.
CN2 —
4 pin connector accepts the cable from the pressure transducer
(UH-200B, UH-200 only).
There are no test points on CN2.
CN3 —
6 pin connector accepts the wiring harness connector.
Connector contains inputs from the thermistor probes.
Disconnect the connector from the board and check thermistor wires
with VOM set to Ohms. Compare with actual temperature of water.
CN4 —
4 pin connector accepts the wiring harness connector.
120VAC test points for:
• Wash tank heat contactor output
• Booster tank heat contactor output
CN5 —
3 pin connector accepts the W/R LED cable from the touchpad/display
on models UH-200B, UH-200 only.
All other models must have a jumper on CN5.
There are no test points on CN5.
T1,T2—
Spade terminals on board.
120VAC test points for power input
• T1 accepts AC Neutral harness wire
• T2 accepts AC Hot harness wire (All models)
T3—
Spade terminal on board accepts wire from Fused Hot T1 terminal on Timer Control
(UH-200B, UH-200 only).
120VAC test point for fused hot.
FUSE—
2 amp fuse to protect 120VAC power output to T1 terminal on Timer Control Board.
This power output is used for the water level control transformer located on the
Timer Control Board on models UH-200B, UH-200 only.
Thermistor Resistance Chart (Approx. Ohms)
80
°
F/27
°
C
=
9,165
90
°
F/32
°
C
=
7,400
100
°
F/38
°
C =
5,775
110
°
F/43
°
C =
4,725
120
°
F/49
°
C =
3,740
130
°
F/55
°
C =
2,985
140
°
F/60
°
C =
2,490
150
°
F/66
°
C
=
2,010
160
°
F/71
°
C
=
1,690
170
°
F/77
°
C
=
1,385
180
°
F/82
°
C
=
1,180
190
°
F/88
°
C
=
975
200
°
F/93
°
C
=
840
210
°
F/99
°
C
=
870
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