Problem

Possible Cause

Action

 

 

Replace fuse, reset breaker. If repeats, check

 

Fuse blown or circuit tripped

fuse or breaker size. Check for shorts in unit

 

 

wiring & components

Unit does not run

Power cord not plugged in

Plug it in

System switch in "OFF" position

Set switch correctly

 

 

Inoperative system switch

Test for continuity in each switch position

 

Loose or disconnected wiring at

Check wiring & connections. Reconnect per

 

switch or other components

wiring diagram

Problem

Possible Cause

Action

 

Dirty fi lter

Clean as recommended in Owner's Manual

 

 

Check for dirty or obstructed coil. Use

 

Restricted airfl ow

pressure wash or biodegradable cleaning

 

 

agent to clean

Evaporator coil

Inoperative t-stat

Test for shorted t-stat or stuck contacts

freezes up

Short of refrigerant

De-ice coil & check for leak

 

Inoperative fan motor

Test fan motor & replace if inoperative

 

 

De-ice coil. Check temp. differential (delta T)

 

Partially restricted capillary tube

across coil. Touch test coil return bends for

 

 

same temp. Test for low running current

Problem

Possible Cause

Action

 

Excessive heat load

Unit undersized. Test cooling performance &

 

replace with larger unit if needed

 

 

 

Restriction in line

Check for partially iced coil & check

 

temperature split across coil

Compressor runs

 

 

Check for oil at silver soldered connections.

continually & does

 

Refrigerant leak

Check for partially iced coil. Check split across

not cycle off

 

coil. Check for low running amperage

 

 

 

T-stat contacts stuck

Check operation of t-stat. Replace if contacts

 

remain closed.

 

 

 

T-stat incorrectly wired

Refer to appropriate wiring diagram

Problem

Possible Cause

Action

 

 

Disconnect power to unit. Remove cover

 

T-stat contacts stuck

of t-stat & check if contacts are stuck. If so,

 

 

replace t-stat

T-stat does not turn

T-stat set at coldest point

Turn to higher temp. setting to see if unit

unit off

 

cycles off

 

Incorrect wiring

Refer to appropriate wiring diagrams

 

Unit undersized for area to be

Refer to industry standard sizing chart

 

cooled

 

 

17

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Image 17
Friedrich RAC-SVC-06 service manual Replace fuse, reset breaker. If repeats, check