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HFC-410A CHARGING INFORMATION – NS18H60M
FOR COMPLETE CHARGING PROCEDURES, REFER TO THE APPLICABLE INSTALLATION AND SERVICE MANUAL
Maintenance checks using the Normal Operating Pressures table
• Table 1 may be used to help perform maintenance checks. This table is not a procedure for charging the system. Minor variations in
the pressures can be expected due to differences in installations. However, significant deviations could mean that the system is not
properly charged or that a problem exists with some component in the system.
Matched System Components/Charge Levels/Line Set Length/Liquid Line Sizing
• Table 2 lists all the GE Appliances recommended indoor unit matches along with the charge levels for the various sizes of outdoor
units. Charge levels on the unit nameplate are based on installations with 15’ (4.6m) line sets; consider line set length and liquid line
sizing differences when calculating charge adjustments. For each additional foot of 3/8” liquid line set, add 0.6 ounces or for 1/2” liquid
lines, add 1.0 ounce of additional charge.
Charge Using the Weigh-in Method
• If the system is void of refrigerant, locate and repair any leaks and then weigh in the refrigerant charge into the unit. For charge
adjustments, be sure to consider line set length differences and, referring to table 2, adjust for the match up difference.
1 – Recover the refrigerant from the unit.
2 – Conduct leak check; evacuate the system.
3 – Weigh in the unit nameplate charge, adjusting for matchup and line set length differences. If weighing facilities are not available,
use the Subcooling method.
Charge Using the Subcooling Method
•
Cooling Mode
- When the outdoor ambient temperature is 60ºF (15ºC) and above, use the cooling mode to adjust the charge using
the subcooling method. Target subcooling values in table 2 are based on 70 - 80ºF (21-27ºC) indoor return air temperature.
•
Heating Mode
- When the outdoor ambient temperature is below 60ºF (15ºC), use the heating mode to adjust the charge using the
subcooling charge levels (table). Target subcooling values in table 2 are based on 65 - 75ºF (18-24ºC) indoor return air temperature.
4 TON MODE
5 TON MODE
ºF
LIQUID LINE PRESSURE /
VAPOR LINE PRESSURE
HEATING OPERATION - MAX SPEED
20
342 / 59
326 / 53
30
345 / 67
347 / 62
40
376 / 82
364 / 75
50
407 / 99
374 / 92
60
422 / 118
392 / 110
COOLING OPERATION - MAX SPEED
65
236 / 134
237 / 121
70
255 / 136
258 / 124
75
276 / 135
278 / 126
80
297 / 136
299 / 127
85
319 / 138
322 / 128
90
344 / 138
345 / 129
95
368 / 140
370 / 129
100
392 / 143
396 / 130
105
418 / 146
423 / 132
110
422 / 147
452 / 133
115
473 / 148
479 / 135
TABLE-1
Normal Operating Pressures
(Liquid ±10 and Suction ±5 psig)
INDOOR MATCHUP
SUBCOOL
ADDNL CHARGE
lbs/oz
HEATING (±5ºF)
COOLING (±5ºF)
4 TON MODE
NAM48*1
23.5
6
8 oz
NAM48*2
20
9
1 lbs 6 oz
NCU(C,U) 48
28
7
0 oz
NCU(C,U) 49
15.5
6.5
10 oz
NCHC48C
17
8
6 oz
INDOOR MATCHUP
SUBCOOL
ADDNL CHARGE
lbs/oz
HEATING (±5ºF)
COOLING (±5ºF)
5 TON MODE
NAM60*1
13
6
7 oz
NAM60*2
11.5
8
1 lbs 2 oz
NCU(C,U) 50/60
28
6.5
1 oz
NCU(C,U) 60C
7
8
9 oz
NCU(C.U) 60D /
9.5
9.5
15 oz
NCHC60D
16
7.5
1 lbs 4 oz
TABLE-2
Indoor Unit Matchups and Subcooling Charge Levels