Checking Charge Refrigerant Amount - Kubota M8540 Workshop Manual

M8540, M9540, WSM

(4) Checking Charge Refrigerant Amount

After charging the refrigerant, check for amount of charging
refrigerant as follows.
NOTE
• The pressure on the following checking is the gauge
indications at ambient temperature 30 °C (86 °F), so it should
be noted that the pressure will differ some what with the
ambient temperature.
1. Disconnect the 1P connector (3) of magnetic clutch.
2. Start the engine and set a approx. 1500 min
3. Connect the 1P connector (3) of magnetic clutch to battery
directly, and then set the blower switch to HI position.
4. Leave the system for approx. 5 minutes until the refrigerant cycle
becomes stable, keeping pressure on the HI pressure side from
1.27 to 1.66 MPa (13 to 17 kgf/cm
5. When the refrigerant cycle is stabilizer, turn off the blower switch
and let the compressor alone to run. Then pressure on the LO
pressure side gradually drops. At this time, if pressure on the HI
pressure side is maintained from 1.27 to 1.66 MPa (13 to 17 kgf/
2
cm , 185 to 242 psi), air bubbles which pass through the sight
glass (7) becomes as stated below depending on refrigerant
charged amount.
Insufficient refrigerant charge
Air bubbles pass continuously the sight glass when pressure on
the LO pressure side is over 99.0 kPa (1.01 kgf/cm
this case, charge the refrigerant from the LO pressure side.
Properly refrigerant charge
Air bubbles pass through the sight glass continuously when
pressure on the LO pressure side is within 59 to 98 kPa (0.6 to 1.0
2
kgf/cm , 9 to 14 psi).
If the charge refrigerant amount is proper, no air bubble is
observed on the sight glass at pressure on the LO pressure side
over 99.0 kPa (1.01 kgf/cm
turned on. When the blower switch is turned off, bubbles pass
through the sight glass in case pressure on the LO pressure side is
within 59 to 98 kPa (0.6 to 1.0 kgf/cm
Excessive refrigerant charge
Air bubbles pass through the sight glass time to time or no air
bubble is observed when pressure on the LO pressure side is under
2
59 kPa (0.6 kgf/cm , 9 psi).
In this case, discharge excessive refrigerant gradually from the
LO pressure side.
(1) LO Pressure Gauge
(2) HI Pressure Gauge
(3) 1P Connector
(4) To Battery
10-S21
-1
(rpm).
2
, 185 to 242 psi).
2
, 14.4 psi). In
2
, 14.4 psi) when the blower switch is
2
, 9 to 14 psi).
(5) HI Pressure Side Valve
(6) LO Pressure Side Valve
(7) Sight Glass
KiSC issued 09, 2008 A
CABIN
W1019604