Problem Solving - Johnson Pump MCHZ Instruction Manual

MCHZ

6 Problem solving

MCHZ/EN (0912) 4.2
Faults in a pump installation can have various causes. The fault may not be in the pump, it
may also be caused by the pipe system or the operating conditions. Firstly, always check
that installation has been executed in accordance with the instructions in this manual and
that the operating conditions still correspond with the specifications for which the pump
was purchased.
In general, breakdowns in a pump installation are attributable to the following causes:
• Faults with the pump.
• Breakdowns or faults in the pipe system.
• Faults due to incorrect installation or commissioning.
• Faults due to incorrect choice of pump.
A number of the most frequently occurring failures as well as their possible causes are
shown in the table below.
Table 2: Most frequently occurring failures.
Most common faults
Pump delivers no liquid
Pump has insufficient volume flow
Pump has insufficient head
Pump stops after start up
Pump has higher power consumption than
normal
Pump has lower power consumption than
normal
The stuffing box packing is leaking
excessively
Packing rings or mechanical seal have to
be replaced to often
Pump vibrates or is noisy
Bearings wear too much or become hot
Pump running rough hot or seizes
Problem solving
Possible causes, see Table 3.
1 2 3 4 5 8 9 10 11 13 14 17 19 20 21
29
1 2 3 4 5 8 9 10 11 13 14 15 17 19 20
21 28 29
2 4 5 13 14 17 19 28 29
1 2 3 4 5 8 9 10 11
12 15 16 17 18 22 23 24 25 26 27 32
34 38 39
13 14 15 16 17 18 20 21 28 29
23 25 26 30 31 32 33 43
23 25 26 30 32 33 34 41
1 9 10 11 15 18 19 20 22 23 24 25 26
27 29 37 38 39 40
23 24 25 26 27 37 38 39 40 42
23 24 25 26 27 34 37 38 39 40 42
25