Carrier 69NT40-541-001, Операция и обслуживание

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T-316 7–26
NOTE
The evaporator fan motors will always start in high speed.
b. Motor running in wrong direction (after checking for correct wiring application).
c. Motor will not start, and IP-Em's are not open.
7.17.2 Removing The Capacitor
WARNING
!
Make sure power to the unit is OFF and power plug disconnected before removing
capacitor(s).
The capacitors are located on the motor and may be removed by two methods:
1. If container is empty , open upper rear panel of the unit. The capacitor may be serviced after disconnecting
power plug.
2. If container is full, turn the unit power OFF and disconnect power plug. Remove the evaporator fan motor
access panel. (See Figure 3.1 ). For removal of the evaporator fan assembly, refer to Figure 7.16 .
WARNING
!
With power OFF discharge the capacitor before disconnecting the circuit wiring.
7.17.3 Checking The Capacitor
If the capacitor is suspected of malfunction, you may choose to simply replace it. Direct replacement requires a
capacitor of the same value. Two methods for checking capacitor function are:
1. Volt-ohmmeter set on RX 10,000 ohms:
Connect ohmmeter leads across the capacitor terminals and observe the meter needle. If the capacitor is good, the
needle will make a rapid swing toward zero resistance and then gradually swing back toward a very high resistance
reading. If the capacitor has failed open, the ohmmeter needle will not move when the meter probes touch the ter-
minals. If the capacitor is shorted, the needle will swing to zero resistance position and stay there.
2. Capacitor analyzer:
The function of the analyzer is to read the microfarad value of a capacitor and to detect insulation breakdown under
load conditions. The important advantages of a analyzer are its ability to locate capacitors that have failed to hold
their microfarad ratings, or those that are breaking down internally during operation. It is also useful in identifying
capacitors when their microfarad rating marks have become unreadable.
7.18 SUCTION MODULATION VALVE
On start up of the unit, the valve will reset to a known open position. This is accomplished by assuming the valve was
fully open, driving it fully closed, resetting the percentage open to zero, then opening to a known 21% staging position.
Figure 7.23 Suction Modulation Valve (SMV)
2 1/8 Inch Nut