Special Precaution When Dealing With R410A Unit; Unit Indicator Lights; Ir Signal Receiver; Cooling Only Unit - McQuay M5WM Series Installation And Maintenance Manual

Special Precautions When
Dealing With R410A Unit
R410A is a new HFC refrigerant which does not damage
the ozone layer. The working pressure of this new
refrigerant is 1.6 times higher than conventional
refrigerant (R22), thus proper installation/servicing is
essential.
• Never use refrigerant other than R410A in an air-
conditioner which designed to operate with R410A.
• POE oil is used as lubricant for R410A compressor,
which is different from the mineral oil used for R22
compressor. During installation or servicing, extra
precaution must be taken not to expose the R410A
system too long to moist air. Residual POE oil in the
piping and components can absorb moisture from the
air.
• To prevent mischarging, the diameter of the service
port on the flare valve is different from that of R22.
• Use tools and materials exclusively for refrigerant
R410A. Tools exclusively for R410A are manifold valve,
charging hose, pressure gauge, gas leak detector, flare
tools, torque wrench, vacuum pump and refrigerant
cylinder.
• As an R410A air conditioner incurs higher pressure
than R22 units, it is essential to choose the copper
pipes correctly. Never use copper pipes thinner than
0.8mm even though they are available in the market.
• If
the refrigerant
installation/servicing, be sure to ventilate fully. If the
refrigerant gas comes into contact with fire, a
poisonous gas may occur.
• When installing or removing an air conditioner, do not
allow air or moisture to remain in the refrigerant cycle.
CAUTION
!
• R410A must be charged as liquid. Usually R410A
cylinder is equipped with a dip-pipe for liquid
withdrawal. If there is no dip-pipe, the cylinder
should be inverted so as to withdraw liquid R410A
from the valve.
• Do not top-up when servicing leak, as this will
reduce the unit performance. Vacuum the unit
thoroughly and then charge the unit with fresh
R410A according to the amount recommended in
the specification.
• Do not touch the compressor or refrigerant piping
when the chiller is running. If necessary wear
protective gloves.
Page 20
gas leakage occurs

Unit Indicator Lights

IR Signal Receiver

When an infrared remote control operating signal is
transmitted, the signal receiver on the indoor unit beeps to
confirm acceptance of the signal transmission.
Figure 21. Indicator Lights Location – Indoor Unit

Cooling Only Unit

Table 6 shows the LED indicator lights for the cooling only
unit under normal operation and fault conditions. The LED
indicator lights are located at the bottom right side of the
indoor unit. (See Figure 21 and Figure 22).
Figure 22. LED Indicator Lights for Cooling Only Unit
during
Table 6. LED Indicator Lights: Normal Operation and Fault
Conditions for Cooling Only Unit
Sleep
Power
Once
every 2
sec.
Twice
every 2
sec.
3 times
every 2
sec.
ON
Mode
or
Timer
Dry
Fault
Timer
Sleep
Dry
Room air
sensor
contact
loose/short
Indoor coil
sensor
contact
loose/short
Sensor coil
problem,
compressor
overload
protection
trip or gas
leak.
/ ON or OFF
IM-5WMF(SEER13)-0706
Action
-
-
-
Repair
or
replace
Repair
or
replace
Check
circuit
breaker,
check
for gas
leak
Blinking