outdoor fan spin and stop in heating mode

[kefah]

hi
i have question about split unit heatpump
why does the outdoor fan spin and stop in heating mode
i know that it stop during defrost mode
but why its spin and stop in normal mode
i encounter this case in all heat pump
when i searched about this state in internet
and i found that this case happen to protect the indoor unit from damage caused by the hi temperature and pressure
but one said that fan stop to allow more cold refrigerant to cool the compressor and prevent the overheating of the compressor
so which opinion is correct
thanks all

[r.bartlett]

it is to reduce the heat load

if the indoor coil sensor notices the indoor unit is not shedding the heat and ending up with a high discharge temp/pressure. By stopping the outdoor fan the duty drops off so the indoor unit can recover back to a normal temp/pressure to prevent potential compressor damage.

[frank]

...and I thought it was for head pressure control.... lol

[kefah]

it is to reduce the heat load

if the indoor coil sensor notices the indoor unit is not shedding the heat and ending up with a high discharge temp/pressure. By stopping the outdoor fan the duty drops off so the indoor unit can recover back to a normal temp/pressure to prevent potential compressor damage.

so you mean it work and stop to protect both compressor and indoor unit from damage

[r.bartlett]

...and I thought it was for head pressure control.... lol

that's a what not a why answer - but you knew that :-)

[r.bartlett]

so you mean it work and stop to protect both compressor and indoor unit from damage

only compressor

[kefah]

only compressor

thank you man