ping pong import split question!!

[totalacedude]

hi guys!

just installed a cheap (throw away) ping pong unit at my mums for her
(god alone knows shy she bought this rubbish)

but i have noticed something that i think shouldnt happen!

when in heating mode every now and then the outside fan will stop and then after a min or so kick back in! (everything else still running)

is this supposed to happen?

have measured the volts going to it and the indoor unit is telling it to do this!!!

still doesnt seem right:(

what do you think guys???

cheers ian :)

[Brian_UK]

Yes, the outdoor fan, evaporator in heat mode, switches in and out to control the load on the compressor.

Common method on a lot of machines.

[Thermatech]

Its called ' over heat protection '

when the indoor unit gets to max coil temp the indoor unit requests outdoor unit stop fan.
If indoor coil stays at or over max coil temp for a set period of time then indoor unit request outdoor unit to stop compressor & restart after restart timer.

This is a form of high pressure control & effectively prevents system from running excessive high pressure if the indoor air filter gets clogged up & poor air flow through the indoor unit coil.

It has been noticed that on some cheap domestic split systems this safety fuction control stratagy is not included & this can result in the system operating at excessive high pressure in heating mode.

However in this case you are running the outdoor unit in summer high outside ambient conditions so the system is operating at higher discharge pressure than winter outside ambient & with this standard control stratagy the operation is most likely correct.

At least this system has this improtant safety function / control statagy
some systems which could be mentioned do not

[totalacedude]

hi thermatech,

i have noticed the fan only kick in and out, not the compressor, compressor stayed on!

i only noticed this because the noise from the outside unit had changed, but upon inspection noticed everything but the fan was running!

regards ian

[acnerd]

My understanding (I'm sure I'll be corrected if wrong ;) ) is that on your average split, the surface area of your condenser is greater than the surface area of the evaporator. So in reverse cycle or heating, you have an "undersized" condenser coil and an "oversized" evaporator coil. As a result in high ambient conditions, if the outdoor fan ran all the time in heating, the "evaporator" would absorb too much heat, which the "condenser" inside would not be able to reject, and thus as Thermatec says, prevents overheating.

I am sure the fan will run full speed in winter as there is less heat in the air to be absorbed.

[totalacedude]

makes total sence now its been explained :)

ta ... ian