Specifications

Adjust the refrigerant charge until the sight glass clears or has only sparse bubbles. The unit

should be allowed to stabilize for several minutes before meaningful measurements can be taken

and the conditioned room should be at or near the temperature setpoint.

All water/glycol cooled units have a water regulating valve. A head pressure transducer is

connected to a shraeder ﬁ tting on the discharge line and water is regulated into the condenser coil.

Plate ﬁ n condensers are standard.

Before starting a compressor, the crankcase heaters should be energized for a minimum of 12

hours to reduce the possibility of liquid slugging on start-up. Failure to energize crankcase heaters

could result in compressor damage.

Note: Charging to a full liquid line sight glass should never be the sole means of determining the

correct refrigerant charge. Other parameters such as superheat, suction pressure, head pressure,

sub-cooling and ambient temperature are also important. A system charged to a clear sight glass

is often overcharged.

5.5 Refrigerant Handling

The use of recovery/recycling units is required by U.S. Environmental Protection Agency (EPA)

regulations. Technicians who service and dispose of air conditioning and refrigeration equipment

must recover the refrigerant instead of venting it to the atmosphere.

Except for extremely small releases of refrigerant such as what occurs when disconnecting

service hoses (diminimous release), a technician who knowingly releases or vents refrigerant to the

atmosphere is in violation of this regulation. Freon purchasers must be certiﬁ ed technicians and

have a valid EPA certiﬁ cation card.

6.0 GLYCOL SYSTEMS

6.1 Glycol Concentration

The system must be ﬁ lled with water and the appropriate amount of ethylene or propylene glycol

to protect against winter freeze-up. To achieve the approximate glycol concentration, it is necessary

to know the total system volume. This consists of the sum of the ﬂ uid cooler volume, the evaporator

unit volume, and the volume of the interconnecting piping.

The following tables can be used for arriving at an approximate system volume. After installation,

the glycol percentage should be checked. The glycol percentage should also be checked at regular

intervals to ensure freeze protection.