Emerson PFH020A-L, User Manual

Page: 29 / 117

Site Preparation and Installation
Liebert
®
Mini-Mate2
™
22
Figure 11 Refrigerant piping diagram
NOTE
When installing remote condensing units below the evaporator, the suction gas line should be
trapped with an inverted trap the height of the evaporator. This prevents refrigerant migration
to the compressor during off cycles.
Table 5 Recommended line sizes, O.D. Cu
Equivalent
ft. (m)
PFH_14A PFH_20A
Suction Liquid Suction Liquid
50 (15.2) 5/8" 3/8" 5/8" 3/8"
75 (22.9) 5/8" 3/8" 7/8" 3/8"
100 (30.5) 7/8" 3/8" 7/8" 3/8"
125 (38.1) 7/8" 3/8" 7/8" 1/2"
150 (45.7) 7/8" 3/8" 7/8" 1/2"
* Suction line and liquid line sizing based on < 3 psi pressure drop in each and suction line refrigerant velocities >700FPM (3.6m/s),
horizontal and 1000FPM (5.1m/s), vertical.
Table 6 Pipe length and condenser elevation relative to evaporator
Nominal System
Size, Tons
Maximum Equiv.
Pipe Length, ft. (m)
Maximum PFH
Level Above
Evaporator, ft. (m)
Maximum PFH
Level Below
Evaporator, ft. (m)
1 or 1.5 150 (45) 40 (12) 15 (4.6)
Maximum recommended total equivalent pipe length is 150 ft (46m). Suction and liquid lines may require additional specialty
items when vertical lines exceed 20 ft. (6m) and/or condensing unit installation is more than 15 ft. (4.6m) below the evaporator.
Contact Emerson Application Engineering for assistance.
Evaporator
Evaporator
Condensing
Unit
NOTE
When installing remote condensing units below the
evaporator, the suction gas line should be trapped with
an inverted trap to the height of the evaporator
. This
prevents refrigerant migration to the compressors
during off cycles
. Maximum recommended vertical
level drop to condensing unit is 15 ft. (4.6m) .
Pitch down 1/2" (13mm) per 10 ft. (3m)
Suction Line Piping
Condensing Unit Above Evaporator
Traps recommended at the base of riser
exceeding
5 ft (1.5m)
and every 20 feet (6m) of vertical rise.
Suction Line Piping
Condensing Unit
Below Evaporator
Condensing
Unit
Pitch down 1/2" (13mm) per 10 ft. (3m)
See Table 6 for recommended maximum
vertical rise above/fall below evaporator.