Controls; Air Conditioning Compressor Protection - MacDon M105 Operator's Manual

3.10.3 Controls

A – Temperature Control Dial controls cab temperature.
• Clockwise: Increases temperature.
• Counterclockwise: Decreases temperature.
B – Blower Switch controls the blower speed.
• OFF / LOW / MEDIUM / HIGH
C – Air Conditioning Switch controls the A/C system.
• OFF: A/C does not operate.
• ON: A/C operates with blower switch ON.
IMPORTANT:
To distribute the refrigerant oil throughout the A/C
system, perform the following steps when starting the
windrower after more than one week of storage:
1. Ensure heater shut-off valve at engine is OPEN. Refer
to
3.10.1 Heater Shut-Off, page
2. Turn blower switch to the first position,
temperature control switch to MAXIMUM heating, and
A/C control to OFF.
3. Start engine and operate at low idle until engine
is warm.
4. Click A/C switch from OFF to ON for 1 second, then
back to OFF for 5 to 10 seconds. Repeat this step
ten times.

3.10.4 Air Conditioning Compressor Protection

The compressor is protected from excessively low and high pressures by two switches that shut down the compressor
to prevent damage to the system.
• The LOW PRESSURE switch opens when the pressure falls to 2–8 psi (14–55 kPa), and shuts down the
compressor. When the pressure rises to 15–25 psi (103–172 kPa), the switch closes, and allows the compressor
to run.
• The HIGH PRESSURE switch opens and stops the compressor when the pressure rises to 315–335 psi
(2172–2310 kPa). When the pressure falls to 220–280 psi (1517–1930 kPa), the switch closes and allows the
compressor to run.
If the air conditioning system is shut down by either switch, locate the source of the problem, and correct it before
operating the system.
169890
OPERATOR'S STATION
47.
turn
48
Figure 3.22: Climate Controls
A - Temperature Control
C - Air Conditioning
B -Blower
Revision A