Heatcraft Refrigeration Products 25006801 User Manual

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Figure 5.  Drain Line

Refrigeration Piping

Suction Lines

 

NOTE:  If the suction line must rise to the point higher than the suction connection on

 

the evaporator, a suction line trap at the outlet of the evaporator must be provided.

Horizontal suction lines should slope away from the evaporator toward the compressor at the rate of 1/4’ per 10 feet 

for good oil return.  When multiple evaporators are connected in series using a common suction line, the branch 

suction lines must enter the top of the common suction line.
Suction lines that are outside of refrigerated space must be insulated.  See “Line Insulation” for more information.

Suction Line Risers

 

NOTE:  To provide proper oil return, a suction trap must be provided at the base of 

 

all suction risers.

Prefabricated wrought copper traps are available, or a trap can be made by using two street ells and one regular ell.  

The suction trap must be the same size as the suction line.  For long vertical risers, additional traps may be necessary.  

Generally, one trap is recommended for each length of pipe (approximately 20 feet) to insure proper oil movement.  

See Figure 4 below for methods of constructing proper suction line P-traps.

Condensate Drain Lines

Copper drain lines should be used and properly protected from freezing.  In running drain lines, provide a minimum 

of 4 inches per foot pitch for proper drainage.  Drain lines should be at least as large as the evaporator drain 

connection.  All plumbing connections should be made in accordance with local plumbing codes.  All condensate 

drain lines must be trapped, and run to an open drain.  They must never be connected directly to the sewer 

systems.  Traps in the drain line must be located in a warm ambient.  We recommend a trap on all evaporators.  Traps 

located outside, or extensive outside runs of drain line must 

be wrapped with a drain line heater.  The heater should be 

connected so that it is continuously on.  It is recommended that 

the drain line be insulated to prevent heat loss.  A heat input 

of 20 watts per lineal foot of drain line for 0ºF (-18°C) room 

applications and 30 watts per lineal foot for -20°F (-29°C) rooms 

is satisfactory.
Inspect the drain pan periodically to insure free drainage of 

condensate.  If the drain pan contains standing water, check for 

proper installation.  The drain pan should be cleaned regularly 

with warm soapy water.

 

WARNING:  All power must be disconnected 

 

before cleaning. The drain pan also serves as

 

cover for hazardous moving parts. Operation 

 

of unit without drain pan constitutes a hazard.

Figure 4.  Suction P-traps

NOTE:  Always trap drain lines individually 

to prevent vapor migration.