Hussmann Krack MS Series - Piping Installation; Drain Line Installation and Setup; Refrigeration Piping Guidelines

MS Series Medium Profile Unit Coolers (E270190_H) 9
6 PIPING INSTALLATION
6.1 DRAIN LINE
The drain line should be as short and as steeply pitched as possible with a minimum of ¼” drop per running foot.
A drain line trap should be installed to prevent warm moist air from migrating through the drain line. If the
temperature surrounding the drain line and trap is below freezing (32) it must be wrapped with a drain line heater
and insulation. Be sure to also wrap the drain pan coupling. The drain line heater must be energized
continuously. Be sure to follow the manufacturer’s recommendation when installing the drain line heat tape.
FIGURE 2: Drain Line
A union at the drain connection in the drain pan is recommended for ease of installation and future servicing. The
union should be located as close to the drain pan as possible, but outside the drain pan space. Use two wrenches
when tightening to prevent the drain fitting from twisting and damaging the unit.
Use drain line hangers to avoid damage to the drain pan with long runs of drain line, i.e. more than a few feet.
FIGURE 3: PIPE JOINING
6.2 REFRIGERATION PIPING
System design must conform to all local and national codes, laws and regulations applying to the site of
installation. In addition, the safety code for mechanical refrigeration, ASME B31.5, should be followed as a
guide to safe installation and operation practice.
Refrigerant line sizes and piping techniques should be obtained from the ASHRAE guide or equivalent reference.
Under no circumstances should the refrigerant connection size of the unit be used as the basis for sizing the lines.
The horizontal suction line should slope away from the unit cooler toward the compressor. Vertical suction risers
may require a trap at the bottom of the riser for proper oil return.
EVAPORATOR
DRAIN PAN
4" to 6"
DRAIN TRAP
CONDENSATE
DRAIN LINE
UNION
DRAIN LINE WRAPPED
WITH INSULATING MATERIAL
THERMOSTATICALLY CONTROLLED
HEATING CABLE
INSULATED
WALL
HEATING CABLE
POWER LINE
VAPOR SEAL THE
PIPE PENETRATION
AND AWAY FROM EVAPORATOR
SLOPE DRAIN PIPE DOWN
WITH ACCESS
( 1/4 INCH PER FOOT OF PIPE )