Carrier DesertMaster 50TJM, Operation And Maintenance

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CONDENSER AND EVAPORATOR-FAN MOTOR BEARINGS – The condenser and evaporator-fan motors have
permanently-sealed bearings, so no field lubrication is necessary.
4.3 – Evaporator Fan Performance Adjustment
NOTE:
To remove belts only, follow Steps 1, 2 & 6. Fan motor pulleys are factory set speed shown in Table 6.
To change fan speeds:
1. Shut off unit power supply.
2. Loosen belt by loosening fan motor mounting plate nuts. Slide the Motor and remove belt.
3. Loosen movable-pulley flange setscrew (see Fig. 8).
4. Screw movable flange toward fixed flange to increase speed and away from fixed flange to decrease speed.
Increasing fan speed increases load on motor. Do not exceed maximum speed specified in Table 6. See Table 7 for
air flow.
5. Set movable flange at nearest keyway of pulley hub and tighten setscrew. (See Table 1 & 6 for speed change for
each full turn of pulley flange.)
6. Replace and tighten belts. See Belt Tension Adjustment section on table 1.
To align fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from mounting plate.
4.4 – Evaporator Fan Service and Replacement
1. Remove supply-air section panel (The bolts holding the flexible connection to the panel should be removed).
2. Remove the Control Side panel.
3. Remove the Belt (refer to the previous section for Belt removal).
4. Remove the locking device of the hub & shaft from the both sides; it can be accessed throw the fan side panel.
5. Pull the shaft gently from the control side, the blower will fall inside the blower housing.
6. Loosen the (lower) first two bolts from each side of the scroll fan housing mid-plate. This can be done from the
supply panel side, now the fan can be removed easily from the supply panel side.
7. To assemble the fan, reverse the above procedure.
Fig. 8 Evaporator – Fan Pulley Alignment and Adjustment
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in damage to components.
1. The compressor is in a Puron® refrigerant system and uses a (POE) lubricant Emkarate RL 32 3MAF. In
the field the oil level could be topped up with Mobil EAL Arctic 22 CC if 3MAF is not available. POE oil is
extremely hygroscopic, meaning it absorbs water readily. POE oils can absorb 15 times as much as
other oils designed for HCFC and CFC refrigerants. Avoid exposure of the oil to the atmosphere.
2. Ensure that system is not subjected to liquid abuse. Turn the crankcase heater on 12 hours before
starting the compressor.
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