11
ADJUSTING SPEED TAP FOR INDOOR BLOWER MOTOR
EEM Motor
The blower motor speed for the EEM motor is controlled by three 24V low voltage leads: green, yellow, and white. The
green lead sets the speed for fan-only mode. The yellow lead sets the speed for cooling and heat pump heating mode (if
applicable). The white lead sets the speed for electric heat mode (emergency heat and second stage heat, if applicable).
The leads are factory connected as follows: Green to T1, Yellow to T2, and White to T3. T1 is the low speed setting and
is dedicated to fan-only mode. T2 is medium speed cooling and T3 is medium speed heating. T4 is high speed cooling
and T5 is high speed heating. To adjust the blower speed, move the yellow and/or white wires to T4 and T5.
NOTE:
If more than one lead is energized at the same time,
the motor will use the higher speed setting.
NOTE:
GPC15 and GPH16 units are rated for a maximum
E.S.P. of 0.8 except when using a 20kw electric heater. (The
maximum static for 20 kW electric heat is 0.5 E.S.P.) When
these units are installed in the 0.5 - 0.8 E.S.P. range, the
white lead (electric heat) must be moved to T5 for proper
operation of the electric heaters.
See CFM vs ESP tables in this manual.
Refrigerant Charge Check (Units with Fixed Orifice Devices)
After completing airflow measurements and adjustments the
unit’s refrigerant charge must be checked. All package units
with fixed orifice devices are charged using the super heat
method at the compressor suction line. After superheat is
adjusted it is recommended to check unit sub-cooling at the
condenser coil liquid line out. For charge adjustments, see
superheat and subcooling charts shown for each model.
SUPERHEAT CAN BE DETERMINED AS FOLLOWS:
1. Read suction pressure. Determine Saturated Suction
Temperature from tables or pressure gauge saturated
temperature scale (R-410A).
2. Read suction line temperature.
3. Use the following formula:
SUPERHEAT = SUCTION LINE TEMP - SAT. SUCTION TEMP.
EXPANSION VALVE (TXV) SYSTEM
SINGLE SPEED APPLICATION
(GPH1624-42)
1. Purge gauge lines. Connect service gauge manifold to
access fittings. Run system at least 10 minutes to allow
pressure to stabilize.
2. Temporarily install thermometer on liquid (small) line near
liquid line access fitting with adequate contact and insulate
for best possible reading.
3. Check subcooling and superheat. Systems with TXV
application should have a subcooling and superheat within
the range listed on the chart.
a. If subcooling and superheat are low,
adjust
TXV then
check subcooling.
b. If subcooling is low and superheat is high,
add
charge
to raise subcooling then check superheat.
c. If subcooling and superheat are high,
adjust
TXV valve then check subcooling.
d. If subcooling is high and superheat is low,
adjust
TXV valve superheat and
remove
charge to lower the subcooling.
The TXV should
NOT
be adjusted at light load conditions 55º to 60ºF, under such conditions only the subcooling can be
evaluated. This is because suction pressure is dependent on indoor air flow, and wet bulb temperature.
SUCTION
PRESSURE
SATURATED
SUCTION
TEMPERATURE
ºF
LIQUID
PRESSURE
SATURATED
LIQUID
TEMPERATURE
ºF
PSIG
R-410A
PSIG
R-410A
50
1
200
70
52
3
210
73
54
4
220
76
56
6
225
78
58
7
235
80
60
8
245
83
62
10
255
85
64
11
265
88
66
13
275
90
68
14
285
92
70
15
295
95
72
16
305
97
74
17
325
101
76
19
355
108
78
20
375
112
80
21
405
118
85
24
415
119
90
26
425
121
95
29
435
123
100
31
445
125
110
36
475
130
120
41
500
134
130
45
525
138
140
49
550
142
150
53
575
145
160
56
600
149
170
60
625
152
SATURATED
SUCTION PRESSURE
TEM PERATURE CHART
SATURATED
LIQUID PRESSURE
TEM PERATURE CHART
TABLE 5
Suction Pressure
Liquid Pressure
Temperature (R-410A)
Temperature (R-410A)
SUBCOOLING = SAT. LINE TEMP - LIQUID LINE TEMP.
