Engineered air EngA CU Series, Инструкция по установке, эксплуатации и обслуживанию

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A
CU MANUAL
IOM-14 43 of 46 Feb 06 R4

On units with sight glasses, check for bubbles. There should be no foaming under steady state
operation.

Water Cooled Condensers - With time, condensers can foul with mineral deposits from the water,
resulting in a reduced heat transfer capacity and increased refrigerant head pressure. Should this
condition occur, the condenser coil should be chemically cleaned or replaced.
Air Cooled Condensers – The external surface of finned coils can be cleaned using a low pressure
water spray and a brush. Coil fins are easily damaged. Do not use high pressure steam or water to
clean coils; it will permanently damage the coil. When using cleaning additives or solutions they
must be compatible with the coil materials or coatings. Use a fin comb to straighten any damaged
or bent fins.

Inspect refrigerant lines for evidence of oil leaks.

Check condenser fans and tighten set screws.
NOTE: Air flow is restricted by dirty coils, dirty filters, slipping fan belts etc. This will reduce cooling
capacity and coil frosting can occur.
ROTOLOCK FITTINGS
It is recommended that systems with compressor Rotolock fittings be checked for tightness according to compressor
manufacturers recommended torque at the start of every cooling season. If the fittings are found to be loose, they
may need to be re-torqued at increased intervals.
Pressure Controls
Encapsulated pressure controls have fixed settings and are not adjustable. Most pressure controls have
the setpoint marked directly on the control. The following table shows typical cut in and cut out setpoint
using saturated temperature; refer to refrigerant specific saturated temperature/pressure tables to
convert to pressure.
TYPICAL SETTINGS (Saturated Temperature)
Pressure Controls Cut In Cut Out
Low Pressure 35°F (1.7°C) 15°F (-9.4°C)
High Pressure Manual 150°F (65.6°C)
High Pressure (Water Cooled) 105°F (40.6°C) 125°F (51.7°C)
Condenser Fan
Various settings to maintain saturated condensing
temperature between 85°F to 125°F (29.4°C to 51.7°C)
Note: Specialized applications or different refrigerants may have pressure control settings outside
typical settings. Refer directly to mounted pressure controls, wiring diagram and/or unit function for
specific details.
Note: Equipment with a receiver can use high pressure controls with the lower setting of than that
noted above, the maximum rated working pressure of the receiver, 90% of the pressure relief valve
rating.