Problem Solving - Atlas Copco LE15 Instruction Book

Instruction book

6 Problem solving

1 Insufficient air pressure
a Air leak
a Check and correct as necessary
b Air filter choked
b Replace filter
c Air pressure switch incorrectly set
c Adjust switch
d Air consumption exceeds maximum output of compressor
d Check equipment connected
e Damaged valve
e Inspect valves and replace parts where necessary
f Unloader 1) malfunctioning
f Inspect and replace parts where necessary
g Solenoid valve 1) out of order
g Remove and check. Replace if necessary
2 Unit does not speed up
a Voltage drop at motor terminals
a Consult power supplier. Use correct size of cable
b Unloader malfunctioning
b See 1f
c Solenoid valve out of order
c See 1g
d Blow-off silencer 1) choked
d Replace
3 Air receiver pressure rises above maximum and causes
safety valve to blow
a Air pressure switch or pilot valve 1) incorrectly set or out
of order
a Check. Replace switch or valve, if necessary
b Solenoid valve defective
b See 1g
c Unloader malfunctioning
c See 1f
d Blow-off silencer choked
d See 2d
4 Relief valve blows 1)
a Defective inlet valve in HP cylinder head
a Inspect and replace part(s) as necessary
b Relief valve not airtight
b Replace valve
5 Receiver does not hold pressure
a Check valve leaks
a Check for broken valve and springs
b Air leaks
b Check and correct as necessary
6 Too frequent starting/too short operating periods
a Air pressure switch or pilot valve 1) incorrectly set
a Increase pressure difference
b Check valve leaks
b See 5a
2920 1257 04
7 High oil consumption on LE/LT compressors
a Oil level too high
a Do not overfill crankcase. Keep level in red circle of sight-
glass
b Piston ring(s) worn or broken
b Have condition of piston rings checked
8 Unit does not start
a Electrical failure
a Have electrical system checked. Check fuses and line
terminals for tightness
b Overload relay cut out
b Reset overload relay. If the relay cuts out again after
starting, see point 9
c Air pressure above pre-set starting pressure
c Compressor will start when air pressure is lower than pre-
set starting pressure of air pressure switch
9 Overload relay cuts out
a Overload relay incorrectly set
a Check and adjust. Reset relay
b Solenoid valve out of order
b See 1g
c Unloader plunger jammed
c See 1f
d Blow-off silencer choked
d See 2d
e Ambient temperature too high
e Improve ventilation of room
f Motor stops and starts too frequently
f See 6
g Overcurrent due to motor or compressor failure
g Have motor line current measured. If currents exceed rated
motor current, have compressor inspected; if currents are
not equal, have motor inspected
Footnote chapter 6
1) If provided.
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