Rfciii Systems; Maintenance - Lennox Diplomat 10HP12 Information

10HP12
OUTDOOR COIL
LIQ. SUC.
ENTERING AIR
+ 10 + 10
TEMPERATURE
PSIG PSIG PSIG
65 F (TXV)
137 78
75 F (TXV) 155 79
85 F (TXV)
182 80
95 F (TXV) 210 82
105 F (TXV)
240 83
65 F (RFC III)
130 59
75 F (RFC III)
155
67
85 F (RFC III)
175 75
95 F (RFC III)
210 82
105 F (RFC III)
240 87
*
For an approved match-up the 10HP60 must be used with a TXV.
2 – RFCIII Systems
The system should not be charged at ambients below
60 _F (15_C). If charging below 60 _F (15_C) is required,
the recommended method of charging is to weigh the
refrigerant into the unit according to the total amount
shown on the unit nameplate and in table 8. For line sets
varying from 20 feet, refer to table 7 for refrigerant charge
adjustment. If ambient temperature is above 60 _F (15_C)
use the subcoooling method outlined below.
SUBCOOLING METHOD (RFCIII SYSTEMS)
(Ambient Temperature Above 60_F [16_C] )
1 – Connect gauge manifold. Connect an upright
R–22 drum to center port of gauge manifold.
2 – Operate indoor and outdoor units in cooling
mode. Allow outdoor unit to run until system
pressures stabilize.
3 – Make sure thermometer well is filled with
mineral oil before
temperature.
4 – Read liquid line pressure and convert to
condensing temperature using temperature/
pressure conversion chart.
Condensing temperature (read from gauges)
should be a few degrees warmer than the
liquid line temperature.
TABLE 12
SUBCOOLING METHOD––RFCIII Systems*
Indoor
Outdoor
Unit
Unit
10HP12 CB/CBH19–21
10HP18 CB/CBH19–21
10HP24 CB/CBH19–26
10HP30 CB/CBH19–31
10HP36 CB/CBH19–41
10HP36 (CAN) CB/CBH19–41
10HP42 CB/CBH19–41
10HP48 CB19–51
*Approved matchups only
5 – Place thermometer in well and read liquid line
temperature. Table 12 shows how much
warmer the condensing temperature should be.
10HP NORMAL OPERATING PRESSURES (COOLING MODE)
10HP18 10HP24 10HP30
LIQ. SUC. LIQ. SUC. LIQ. SUC.
+ 10 + 10 + 10 + 10 + 10 + 10
PSIG PSIG PSIG PSIG PSIG
145 72 160 74 170
165 73 185 76 195
195 74 215 78 225
225 77 245 80 255
255 79 275 84 290
150 61 150 60 165
170 68 175 67 190
195 75 205 73 220
230 81 240 78 255
260 85 280 81 285
checking liquid
Condensing Temp F Warmer
Than Liquid Line At Various
Ambients
65_F 75_F 85_F 95_F 105_F 115_F
5 5 4 1 0
13 13 13 12 6
12 12 11 9 7
12 12 10 8 6
17 15 14 11 8
18 16 15 12 9
11 10 7 6 4
11 10 8 7 5
TABLE 11
10HP36 10HP36 (CAN)
LIQ. SUC. LIQ. SUC.
+ 10 + 10 + 10 + 10
PSIG PSIG PSIG PSIG
75 175 75 175 76
77 200 76 200 77
78 227 77 230 78
80 260 79 260 79
82 295 81 295 81
62 170 61 160 62
69 205 68 190 68
74 230 73 225 70
80 265 79 255 77
84 305 82 385 81
Add refrigerant to make the liquid line
temperature cooler.
Recover refrigerant to make the liquid line
temperature warmer.
6 – When unit is properly charged liquid line
pressures should approximate table 11.
E – Oil Charge
Refer to table 4 on page 6 for factory oil charge.
V – MAINTENANCE
At the beginning of each heating or cooling season, the
system should be cleaned as follows:
A – Outdoor Unit
1 – Clean and inspect outdoor coil. (Coil may be
flushed with a water hose).
2 – Outdoor fan motor is prelubricated and sealed.
No further lubrication is required.
3 – Visually inspect all connecting lines, joints
line
and coils for evidence of oil leaks.
NOTE-If insufficient heating or cooling occurs, unit
should be gauged and refrigerant charge checked.
B – Indoor Coil
1 – Clean coil if necessary.
2 – Check connecting lines, joints and coil for
evidence of oil leaks.
3 – Check condensate line and clean if necessary.
C – Indoor Unit
1 – Clean or change filters.
2 – Check blower motor for debris. Blower motors
are prelubricated and sealed. No further
lubrication required.
0
4 3 – Adjust blower speed for cooling. Static
5
pressure drop over the coil should be checked
4
to determine the correct blower CFM. Refer to
5
6
Lennox Engineering Handbook for Static
2
Pressure and CFM tables.
2
4 – Check all wiring for loose connections.
5 – Check for correct voltage at unit.
6 – Check amp–draw on blower motor.
Unit nameplate_________Actual_________.
Page 14
10HP42 10HP48
LIQ. SUC. LIQ. SUC.
+ 10 + 10 + 10 + 10
PSIG PSIG PSIG PSIG
160 72 165 72
185 74 185 73
215 76 210 76
245 78 240 78
280 80 275 80
155 61 155 63
180 63 185 64
210 68 210 69
240 73 245 74
275 76 275 78
10HP60
LIQ. SUC.
+ 10 + 10
PSIG PSIG
150 73
175 75
200 76
235 78
265 80
*
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