Possible Problems At Commissioning - Carrier 30PA 90 Installation, Operation And Maintenance Instructions

11 - COMMISSIONING
Control of the refrigerant load
■ When starting the compressor, check the subcooling and
overheating and thus verify is the refrigerant load is appropriate
to the operation conditions.
■ If the refrigerant load is lower than required, the suction
pressure will be rather lower than normal, and overheating when
suctioning from the compressors will be high. This can cause
an interruption in operation due to activation of the refrigerant
load safety device.
To adjust the refrigerant load, a schrader valve is built into the
unit on the liquid line.
Revovery circuit
water outlet
Low-pressure schrader valve
(optional pressure gauge connection)
Low-pressure
pressostat
High-pressure
pressostat
High-pressure schrader valve
(optional pressure gauge connection)
■ Verify the absence of any leaks of the refrigerant. In the event
of a leak:
Indoor circuit Revovery circuit
water inlet water inlet
Indoor circuit
water outlet
Electric
panel
- Completely empty the unit using a specifi c recovery unit for
R-410A and repair the leak.
- Next, reload the gas into the unit according to load data
provided in the technical characteristics table and in the
unit's data plate.
- Add the refrigerant via the schrader valve of the liquid
line using the appropriate equipment and tools, with the
compressor stopped, monitoring the pressures to control
any anomaly.
Schrader valve for
refrigerant load

Possible problems at commissioning

All indications given in this brochure must be respected and
complied with to guarantee a correct operation of the units.
Next, several possible operation problems are stated which could
happen if the conditions of the commissioning are not appropriate.
■ Insufficient water flow. Very high temperature differences
between water inlet into and outlet from the unit caused by:
- Insuffi cient air bleeding.
- Small water circulation pump or anti-clockwise rotation.
- Other situations which may prevent correct water circulation.
Door
■ Insuffi cient thermal charge in the installation. The limiting
switch
operating values are quickly reached by:
- Incorrect operation of the emissions system (fan coils, air
conditioning exchangers, etc.).
■ Air recirculation in the unit, originated by some obstacle in the
air aspiration or supply.
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