SYSTEM START-UP
ENERGIZE CRANKCASE HEATER
This unit is equipped with crankcase heaters for both the lead
and follower compressors. The operation of the crankcase
heater is monitored by means of the control board.
CAUTION: An attempt to start the compressor without at least
8 hours of crankcase heat will damage the com-
pressor.
A warning label with an adhesive back is supplied in the unit
installation instruction packet. This label should be attached to
the field supplied disconnect switch where it will be easily seen.
See below.
In order to energize the crankcase heater:
- Set indoor two stage cooling thermostat to "OFF" position.
- Close the line power disconnect to the unit.
CHECKING SYSTEM CHARGE
The factory charge in the outdoor unit is listed in the Table 5 as
well as unit nameplate and includes enough charge for the unit
and the corresponding indoor evaporator coil. This unit in-
cludes sufficient charge for 15 feet of line sets. Table 6 lists the
refrigerant line charges for additional lengths.
CAUTION:
REFRIGERANT CHARGING SHOULD ONLY BE
CARRIED OUT BY A QUALIFIED AIR CONDI-
TIONING CONTRACTOR.
In order to check whether the unit has the required charge in
the system, follow the procedure described below.
WARNING:DO NOT VENT REFRIGERANT TO THE ATMOS-
PHERE. IT IS NECESSARY TO RECOVER THE
REFRIGERANT DURING ANY REPAIR OR IN-
STALLATION OF THE SYSTEM.
1. Set room thermostat at desired temperature. The thermo-
stat may be energized at first (Y1) stage or second (Y2)
stage. If only the first stage (Y1) is energized, only the lead
compressor will be in operation. Both the compressors will
be in operation if the second stage of thermostat (Y2) is
energized.
Set room thermostat at "COOL" position and fan switch at
"AUTO" or "FAN" position. There is a five minute delay
when the "system control board" is powered for the first
time. Refer to "System Functions" for more information
about time delays.
2. Operate the unit for a minimum of 15-20 minutes before
checking the charge.
3. Verify the desired indoor air handler air flow (CFM).
4. The system charge should be varified with only the lead
compressor running, however it can be also checked with
both the compressors running at the same time at the rated
indoor air handler air flow. However, it is required to estab-
lish the subcooling level at any one condition i.e. either with
the lead compressor running or when both (the lead and
follower) compressors are running.Recommended sub-
cooling temperature is listed in Table 3.
MODEL
RECOMMENDED SUBCOOLING
°
F
LEAD
COMPRESSOR
ONLY
LEAD + FOLLOWER*
(BOTH)
COMPR. RUNNING
H1DS036
10
18
H1DS048
10
18
H1DS060
10
18
*Lead compressor is designated / labeled as the # 1 com-
pressor. Follower compressor is the # 2 compressor.
TABLE 3 - RECOMMENDED SUBCOOLING
LIQUID
PRESSURE
(PSIG) @
SERVICE
PORT
Required Subcooling Temp.
°
F
LIQUID
PRESSURE
(PSIG) @
SERVICE
PORT
Required Subcooling Temp.
°
F
5
10
12
15
20
5
10
12
15
20
Liquid Line Temperature
°
F
Liquid Line Temperature
°
F
139
73
68
66
63
58
264
116
111
109
106
101
146
76
71
69
66
61
271
117
112
110
107
102
153
79
73
71
68
63
276
120
115
113
110
105
161
82
77
75
72
67
285
122
117
115
112
107
166
85
90
88
85
80
301
126
121
119
116
111
179
89
84
82
79
74
309
127
122
120
117
112
187
92
87
85
82
77
317
130
125
123
120
115
196
95
90
88
85
80
325
132
127
125
122
117
202
97
92
90
87
82
333
134
129
127
124
119
208
99
94
92
89
84
342
136
131
129
126
121
220
103
98
96
93
88
350
138
133
131
128
123
229
106
101
99
96
91
359
140
135
133
130
125
236
108
103
101
98
93
368
142
137
135
132
127
246
111
106
104
101
96
377
144
139
137
134
129
256
114
109
107
104
99
386
146
141
139
136
131
TABLE 4 - SUB-COOLING CHART
IMPORTANT
IF POWER HAS BEEN OFF FOR 8 HOURS OR LONGER,
DISCONNECT SWITCH MUST BE TURNED ON 8 HOURS
BEFORE THERMOSTAT IS SET TO “HEAT”,"COOL" OR
“AUTO”
035-03095.
550.37-N1Y
Central Environmental Systems
9
