9
521B0881 DKCFN.PI.020.F1.02
12. Trouble Shooting
Motor does not start:
• Check power supply
• Check start permission from control system
• FCM 300:
o Check programming
o Is a start signal applied to terminal 4?
o Is the supply pressure sufficient?
o Is the water temperature below 50°C/122°F
o Is line 2 blinking when using an LCP? If so, press START
o Reset the FCM after a fault or trip condition
Pump does not generate pressure:
• Check water supply:
o Ball valve open?
o Supply pressure OK?
o Filter OK, not clogged?
• Repeat bleeding procedure
o Bleed the filter
o Bleed the pump
• Check application:
o Is any dump valve open?
o Are all nozzles properly installed and tight?
o Is there still any air in pipes and hoses?
• After pump replacement:
o Have the installation instructions for the pump been observed?
o Has the flexible coupling between motor and pump been
installed properly? No axial load is tolerated!
Pump generates too low pressure:
• Is the pressure relief valve properly adjusted?
• Is the FCM 300 pressure set point programmed correctly?
• Are there any leakages in the system?
• Do all nozzles spray as expected?
• Is the Plug&Spray
TM
unit properly sized in relation to the nozzles?
Pump is noisy:
• A noisy pump is often a sign of cavitation.
o Is the system properly bleeded?
o Is the supply pressure sufficient?
o In case of a mechanical failure, stop the pump immediately and
return it for inspection.
Pressure decreases over time:
• The pump is providing less and less pressure over time.
o Has the resistance of the nozzles changed?
o Are there any leakages in the system?
o Is the pressure relief valve still adjusted correctly?
o The pump may have reached its service life and requires a
refurbishment.
11. Maintenance
11.1 Filter replacement:
The supply pressure manometer allows to check the supply pressure
and to monitor it for preventative maintenance, e.g. changing filter.
When the pressure drop across the filter increases over time as the
filter becomes dirty, the pressure will decrease. To avoid an unforeseen
system stop, replace the filter cartridge before reaching the cut-off
pressure level of 1.6 bar (23 psi).
• Use only original Danfoss spare part
• Shut the ball valve
• Relief pressure from the system by pressing the red button
• Remove the filter housing and the used cartridge
• Attach the gaskets on both ends (thin type) to the new cartridge
• Insert the new cartridge
• Please be careful with the O-ring in the filter housing
• Turn the filter house carefully when reapplying
• Make sure that the gasket stays in proper position
• Only hand tighten the filter house, do not use a tool!
Never run the system without filter cartridge! Improper filtration
may result in severe damage or reduced lifetime. Danfoss will not
accept warranty claims due to contamination.
11.2 Pump replacement
Nessie pumps are maintenance-free. Under normal operation conditi-
ons and with sufficient filtration, the pump service life is at least 8000
operating hours. Only when the pump performance is decreasing or
the noise level increasing, the pump should be replaced immediately.
In systems with high availability demands, Danfoss recommends a
preventive pump replacement after 8000 operating hours.
The replacement must only be made by an authorized Danfoss service
partner.
11.3 Decommissioning
Humidification and adiabatic cooling systems are often seasonally
operated. This may result in longer periods of no operation and the
following problems:
• Hygiene problems due to bacteria growth (bio film)
• Corrosion of vital parts (if air accumulates in the system over time)
The best way to avoid both problems is to run the system - although
not needed - for a couple of minutes every day to entirely replace the
water in the system. An optional drain valve may be installed to drain
the system to the sewer. If this is not feasible, the system should be
preserved as described in the following chapter about frost protection.
11.4 Frost protection:
If the Plug&Spray
TM
unit is exposed to temperatures below freezing,
the system must be frost protected with a glycol mixture (minimum
35% of monopropylene glycol).
Follow this procedure:
• Disconnect the water supply; connect the supply to a canister with
glycol mixture
• Drain the system as much as possible, remove the filter housing to
drain it
• Connect the high-pressure discharge to the same canister with
glycol mixture
• Briefly run the pump pressure-less to entirely fill the system with
glycol mixture
• To re-commission, flush the system as described above
• It is recommended to renew the filter cartridge shortly after re-com-
missioning!
Never just drain the system! Remaining water will result in corrosion
and damage! Always refill the system with water or glycol mixture.
