Takeuchi TB175W, Руководство по ремонту

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III-65 TB175W
These readings at the vents will be higher and temperature swing slow-
er and not as obvious. Also blower speed will cause the temperature,
levels to read higher (high air speed) or lower (low air speed) at the
same thermostat setting. When you measure air temperature, an elec-
tronic thermometer/pyrometer is a great tool to have. You can easily
measure cab air temperature at several locations quickly.
Swing temperatures vary depending on where you measure tem-
perature, and on outside temperature, humidity and altitude. The chart
in Figure 7-6, shows some examples of typical temperature variables.
Don’t forget that cab and sleeper area temperatures can vary within the
same vehicle. Also, electronic controls used in newer HVAC systems
often keep the temperature spread within a narrower range.
2. Check Clutch Cycling Under Load
The following operating inspections, visual and by feel, are done outside the
cab while you wait for the system to stabilize.
A. Lift hood – With the hood up (or cab tilted) observe the clutch cy-
cling under load.
Note: If the condenser is hood mounted you may not have adequate
air flow through it.
B. Touch suction and discharge lines – Soon after system start up you
can safely feel the suction and discharge lines and note their change in
temperature. The discharge line will get hot (after a while it may be to
hot to touch) and the suction line will get cooler.
3. Check Sight Glass
The sight glass is the only point where you can actually see inside the air
conditioner during operation. Check the sight glass through the window on
the top of the receiver-drier (or the separate in-line sight glass). If the sys-
tem is functioning properly and cooling the cab adequately, the sight glass
should be clear (you will not see anything in it). If it is not clear when the
system is first turned on, wait a few minutes for the system to stabilize, then
look again. Figure 7-7 illustrates and explains what you may observe in the
sight glass. Roof mounted condenser fans may run continuously or cycle on
and off. If you can’t tell by sound you may have to climb a ladder and ob-
serve the fan blades.
Inspection & Maintenance
Figure 7-6
The chart of AC system and
cab temperature range shows
you typical variables.
AIr tEMp.
dEgrEES f.
AIr quAlIty
CEntEr OutlEt
AIr tEMp.
dEgrEES f.
OutlEt AIr tEMp.
rAngE dEgrEES f.
huMId
70° 80° 90° 100°
dry
43°
to
47°
lEfT & RIghT AIR OUTlET TEMPERATURE wIll VARY
40°
to
41°
lEft rIght lEft rIght lEft rIght lEft rIght
huMId dry huMId dry huMId dry
40°
to
44°
44°
to
48°
40°
to
44°
47°
to
51°
40°
to
44°
52°
to
56°
41°
to
45°
41°
to
44°
41°
to
45°
43°
to
47°
46°
to
52°
47°
to
54°
48°
to
55°
50°
to
56°