Danfoss Heat Pump Troubleshooting Guide download pdf (Page 30)

VMIFB202

Build-up of ice under and around the outdoor unit or water collecting

Action:

Drain the ground under and around the outdoor unit so that it can cope with the extra amount of water produced because

of defrosting. During some periods when the outdoor unit is being defrosted, large amounts (20-40 L/day) of water can run o.

One can also install a drip tray with a drainpipe routed to an indoor drain or gully.

NOTE! A heating cable will probably have to be installed in the drainpipe.

If one has an Atria newer than week 34 2008 there is a base for the driptray and a further terminal block to connect a heating cable for

the drip tray but it is conditional on the drip tray having a relay kit.

If one has an Atria older than week 34 2008 there is not a drip tray with electricity that is suitable for the stand.

Positioning the outdoor unit

Action:

Determine whether the outdoor unit can be moved to a more suitable location.

When positioning the outdoor unit, its direction does not aect its performance. The outdoor unit does not need to be positioned as

close to the heat pump as possible. See the following instruction for distance between the heat pump and outdoor unit.

Connection/wall lead-ins

Action:

Check that the unit is installed according to the installation instructions and that the outdoor unit is secured to the wall.

Rigid mountings can generate noise from the outdoor section via walls in the house.

Defrosting problems

Action:

For a defrosting to occur the control computer calculates the dierence between the defrost sensor and brine in. On older models

there is no defrost sensor, the outdoor sensor is used. So when the brine in is too cold compared to the outdoor temperature the

control computer knows that the outdoor unit is frosted with too much frost to retrieve the energy in the air and then wants to defrost

the outdoor unit to obtain as ecient energy retrieval as possible. When brine in reaches the limit for defrosting the defrost shunt

starts to open and will send out a defrosting temperature on brine out of between 11-20 degrees (depending on model year). Defrost-

ing stops when the brine in reaches 9-11 degrees (depending on model year) or time, which is 10 minutes. Our recommendation is to

use temperatures as close to each other as possible for example 15 degrees out and 11 degrees in. During defrosting the compressor

stops if it runs against the heating system. If the heat pump runs against the hot water when the defrosting starts the compressor

continues to run. Because one uses the outer jacket for the hot water when defrosting.

Brine temperature in/out displays faults

Action:

Measurement check the temperatures with a digital thermometer.

Go into manual test and only start the brine pump and see if the sensors display the same after a few minutes.

If necessary, calibrate Brine In and Brine Out in the heat pump’s control computer or replace sensors.

Troubleshooting Guide Outdoor unit and defrosting problems

1 2 ... 25 26 27 28 29 30 31 32 33 34

No comments

Danfoss Heat Pump Troubleshooting Guide Page 30