Carrier Gemini 38AU07 Series, Installation Instructions Manual, Page: 9 / 52

9
Table 8 — 38AUD Piping Recommendations (Dual-Circuit)
LEGEND
Table 9 — 38AUDC12 Hot Gas Bypass Piping Recommendations (Dual-Circuit)
NOTES:
1. 38AUDC units re q uire TWO sets of refrigeration piping.
2. For applications with e q uivalent length greater than 188 ft. (57 m.)
and/or linear length greater than 125 ft. (38 m.), contact your local
Carrier representative.
MODEL AND
NOMINAL
CAPACITY
LINEAR LINE
(ft (mm))
0 - 25
(0-8)
25 - 50 50 - 75 75 - 100 100 - 125 125 - 150 150 - 175 175 - 200
EQUIV. LINE
(FT (MM))
0 - 38 38 - 75 75 - 113 113 - 150 150 - 188 188 - 225 225 - 263 263 - 300
38AUD--12
Liquid Line Size (in.) 3 /
8
" 3 /
8
" 3 /
8
" 3 /
8
" 1 /
2
" 3 /
8
" 1 /
2
" 3 /
8
" 1 /
2
" 1 /
2
" 5 /
8
" 1 /
2
" 5 /
8
"
Liquid PD (F) 1.4 2.7 5.5 5.5 0.9 6.9 1.1 8.2 1.4 1.6 0.5 1.8 0.5
Max Lift (ft) 25 50 75 82 100 66 125 49 133 130 144 128 144
Max Lift PD (F) 3.4 6.8 10.2 12.1 9.0 12.1 11.2 12.1 12.1 12.1 12.1 12.1 12.1
Suction Line Size (in.) 3 /
4
" 7 /
8
" 7 /
8
" 7 /
8
" 1 1 /
8
" 7 /
8
" 1 1 /
8
" 1 1 /
8
" 1 1 /
8
" 1 1 /
8
"
Suction Ln PD
(F) (Cap Red)
1.4 1.2 1.8
2.5
(-0.8%)
0.8
3.1
(-1.9%)
0.9 1.1 1.3 1.5
Charge (lb) 9.0 10.0 11.0 12.1 15.7 13.1 17.7 14.9 19.6 21.5 28.2 23.5 31.0
#/TR 0.73 0.81 0.89 0.97 1.27 1.05 1.42 1.20 1.58 1.74 2.27 1.89 2.50
38AUD--14
Liquid Line Size (in.) 3 /
8
" 3 /
8
" 3 /
8
" 3 /
8
" 1 /
2
" 3 /
8
" 1 /
2
" 1 /
2
" 1 /
2
" 5 /
8
" 1 /
2
" 5 /
8
"
Liquid PD (F) 2.1 4.1 6.2 8.2 1.5 10.3 1.8 2.2 2.6 0.7 2.9 0.8
Max Lift (ft) 128 50 75 69 155 42 125 145 140 163 135 162
Max Lift PD (F) 4.0 8.1 12.1 13.6 9.4 13.6 11.7 13.6 13.6 13.6 13.6 13.6
Suction Line Size (in.)
7
/
8
"
7
/
8
"
7
/
8
" 1
1
/
8
" 1
1
/
8
" 1
1
/
8
" 1
1
/
8
" 1
1
/
8
" 1
1
/
8
"
Suction Ln PD
(F) (Cap Red)
1.0 1.9
2.9
(-1.5%)
0.8 1.1 1.4 1.6 1.9
2.2
(-0.3%)
0.7
Charge (lb) 17.0 18.0 19.0 19.5 20.6 23.7 21.8 25.7 27.6 29.5 36.2 31.5 39.0
#/TR 1.36 1.44 1.52 1.56 1.65 1.90 1.74 2.05 2.21 2.36 2.89 2.52 3.12
#/TR — Charge to unit capacity ratio, lbs per ton (at 45°F SST, 95°F ODA)
Cap Red — Capacity reduction caused by suction line pressure drop > 2°F
Liquid PD (F) — Li q uid line pressure drop, saturated temperature, degrees F
Max Lift — Maximum li q uid lift (Indoor unit ABOVE outdoor unit only), at maximum permitted pressure drop.
Max Lift PD (F) — Pressure drop including Maximum li q uid lift value
ODA — Outdoor Air
SC — Sub-cooling, degrees F (at li q uid line valve)
SST — Saturated Suction Temperature
Suction Ln PD (F) — Suction Line Pressure Drop, saturated temperature, degree F
TC — Total Capacity, MBH (at 45°F Saturated suction, 95°F outdoor air temp)
MODEL AND
NOMINAL
CAPACITY
Linear Line (ft (mm)) 0-25 (0-8) 25-50 (8-15) 50-75 (15-23) 75-100 (23-30) 100-125 (30-38)
Equiv. Line (ft (mm)) 0-38 (0-12) 38-75 (12-23) 75-113 (23-34) 113-150 (34-46) 150-188 (46-57)
38AUDA/B12
Liquid Line Size (in.)
3 /
8
3 /
8
3 /
8
3 /
8
1 /
2
3 /
8
1 /
2
Pressure Drop (°F)
1.8 3.5 5.2 8.7 1.2 8.7 1.5
Max Lift (ft)
25 50 57 65 100 62 125
Pressure Drop (°F)
3.8 7.5 11.3 12.2 9.4 13.7 11.7
Suction Line Size (in.)
Circuit 1:
Vapor riser required, not greater than 20 ft (6.1 m) — See Fig. 5
Tube S
5 /
8
in
.
1 1 /
8
in
.
1 3 /
8
in
.
1 3 /
8
in
.
1 3 /
8
in
.
Tube A
5 /
8
in
.
5 /
8
in
.
5 /
8
in
.
5 /
8
in
.
5 /
8
in
.
Pressure Drop (°F)
2.0 2.0 1.9 2.0 2.0
Circuit 1:
Vapor riser greater than 20 ft (6.1 m) — See Fig. 6
Tube S
5 /
8
in
.
7 /
8
in
.
Tube A
5 /
8
in
.
5 /
8
in
.
5 /
8
in
.
5 /
8
in
.
5 /
8
in
.
Tube B
NR 1 /
2
in
.
5 /
8
in
.
5 /
8
in
.
5 /
8
in
.
Pressure Drop (°F)
1.6 1.7 1.7 2.1
Circuit 1:
No vapor riser required
7 /
8
in
.
7 /
8
in
.
1 1 /
8
in
.
1 1 /
8
in
.
1 1 /
8
in
.
Circuit 2:
7 /
8
in
.
7 /
8
in
.
1 1 /
8
in
.
1 1 /
8
in
.
1 1 /
8
in
.
Pressure Drop (°F)
1.1 2.1 0.9 1.2 1.5
Charge (lb) 1/2
13.3 14.3 15.8 16.9 20.0 18.1 22.0