Carrier Weathermaster 48P030-100 Controls, Start-Up, Operation, Service, And Troubleshooting page 277

APPENDIX I — OPTIONAL GREENSPEED/LOW AMBIENT CONTROL (CONT)
VFD Maintenance
If installed in an appropriate environment, the VFD requires very
little maintenance. Table BK lists the routine maintenance inter-
vals recommended by Carrier.
Table BK — Maintenance Intervals
MAINTENANCE
Heat Sink Temperature Check and
Cleaning
Main Cooling Fan Replacement
Internal Enclosure Cooling Fan
Replacement
Capacitor Change (Frame Size R5 and R6) Every ten years
HVAC Control Panel Battery Change
HEAT SINK
The heat sink fins accumulate dust from the cooling air. Since a
dusty sink is less efficient at cooling the drive, overtemperature
faults become more likely. In a normal environment check the heat
sink annually, in a dusty environment check more often.
To clean the heat sink on AHC550 VFDs:
1. Turn off and lock out unit power.
2. Remove the drive cover (see Fig. AQ).
3. Press together the retaining clips on the top cover and lift
(see Fig. AR).
4. Blow clean compressed air (not humid) from bottom to top
while simultaneously using a vacuum cleaner at the air
outlet to trap the dust.
5. Replace the cooling fan.
6. Replace the drive cover.
7. Restore power.
To clean the heat sink on ASC320 VFDs:
1. Turn off and lock out unit power.
2. Insert a small straight blade screwdriver into the slot and
press in to release the top cover as shown in Fig. AS.
3. Blow clean compressed air (not humid) from top of
ASC320 while simultaneously using a vacuum cleaner at
the base to trap the dust.
4. Replace the top cover.
5. Restore power.
Captive
Screw
Fig. AQ — Remove ACH550 VFD Front Cover
INTERVAL
Every 6 to 12 months (depending 
on the dustiness of the environment)
Every five years
Every three years
Every ten years
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Fig. AR — Remove Top Cover on ACH550 VFD
Fig. AS — Remove Top Cover on ASC320 VFD
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