Troubleshooting And Scrapping Criteria; General Safety Information; Operational Conditions Which Can Cause Pump Failures; Mechanical Failure - Danfoss APP Series Installation, Operation And Maintenance Manual

Operation guide
8. Troubleshooting and

scrapping criteria

© Danfoss | 2023.03
Installation, Operation and Maintenance APP 53-92 pumps

8.1 General safety information

Before inspecting the pump unit, it is necessary
to read and understand this user manual,
especially the Safety chapter 2.
Remember to wear suitable safety equipment
according to Safety chapter 2.
8.2 Operational conditions which can cause
pump failures
The following conditions can cause a pump
failure :
• The pump is running dry.
• The inlet pressure is too high.
• The inlet pressure is too low.
• The temperature of the fluid is too high.
• The ambient temperature is too high.
• The pump is running against a blocked
port/closed manual valve.
• The pump is operating at a pressure out of
specification.
• The pump is running with a non-specified/
approved fluid.
• The pump is running in the wrong
direction.
• The filtration is insufficient.
• The pump is not being serviced according
to Danfoss specifications (end of life).
• There is excessive mechanical load on the
shaft coupling and piping.

8.3 Mechanical failure

If the pump is running dry, the temperature will
quickly increase which can cause burns.
If there is any leakage at start-up or during
operation, a high-pressure jet can cause eye or
skin damage.
Leakage can result in flooding, which can cause
slipping, tripping or falling.
If water is leaking into the electric motor; it can
cause electric shock, fire, short circuit or even
death. When mounting the pump vertically
always mount the motor above the pump to
avoid water leaking into the electric motor.

8.4 Electrical failure

If the wiring of the electric motor is incorrect or
the ground connection is missing, it can cause
electric shock, burn damages, fire or even death.
If a VFD is used and wrongly programmed, it can
damage the pump and lead to high tempera-
tures or other dangers.
All electrical installation must be carried out by
authorized personnel in accordance with
EN60204-1 and/or local regulations.

8.5 Responsibility

Danfoss takes no responsibility for any abnormal
injuries, risks or damages that could arise caused
by abnormal conditions, vibrations, corrosion,
abrasives, foreign objects or excessive tempera-
tures and shall not be liable for any consequen-
tial or incidental damages.
8.6 Scrapping criteria
Whether the pump can be repaired or need to be
scrapped, depends on in which conditions the
internal parts are, or how damaged the whole
unit is. Please use appendix 6, Trouble shooting
guide as guideline or send the pump to Danfoss
headquarter in Denmark for evaluation.
For other observations or troubles, please see
appendix 7, Right and Wrong which gives good
advises regarding design, installation, wiring and
troubleshooting.
In case the pump needs to be scrapped, please
follow your local environmental rules.
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