atlas copco dryer problem

[paul441]

Hi all

can anyone give me some advice on a dryer problem,I av put an new compressor in this unit today anyway when tried to charge system it only pulls in .07 and should be 3kg r410a unit switched on for comp to pull rest in but it wont take anymore this unit has hotbypass soleniod which i checked and its not energiseing would this be the problem why i cant get charge in , any help would be grateful as i am fairly new to working on dryers

cheers

[Tayters]

Never worked on a drier myself so just thinking out load here. Have you blocked a discharge pipe with braze? Does the compressor make the same noise as before?

I would imagine the HGBV would energise to pass discharge gas to suction raise suction pressure. This would create a false load or help when starting compressor. Either way I don't see how it would affect your problem as you should still have a refrigeration circuit.

Can you reclaim and blow through with OFN and check with stratigically placed gagues if OFN is getting all the way round?

Hope that helps,
Andy.

[glenn1340]

Hi Paul,
I take it this must be a recent unit as I`ve not come across any with R410a. On other dryers I`ve charged I`ve not had any problems with any type of HGBV. You say you`re pulling in the refrigerant, it might be an idea to use a heater band to increase the cylinder pressure. In theory on a vacced out system the charge should flow in easily until the pressures equalize....but there again theory doesn`t always work in practice.
By the way, my son had trouble charging a small dryer where he`d fitted a new pump (only point was on the stub fitted to the pump) He phone me up as he`d tried everything to get the gas in. After a few questions it turned out that he`d had trouble getting the schreader valve stub to solder in....he`d fed so much solder in he`d blocked the copper pipe. After he replaced it the dryer charged ok.
I`m not saying that you`ve blocked a pipe with solder but just be open to any possibilities

[Magoo]

Generally speaking, driers have a evap pressure reg valv and hot gas injection to maintain a evap pressure relative to dew point and not freeze up evaporator so as to maximize moisture removal.
Sounds like the hot gas valve is passing despite not being energized and keeping suction at compressor highish, what has possibly killed the original compressor, high suction superheat.
Suggest recovering what charge already charged into system, then evacuate total system, then dump charge required system charge with liquid into high side, then operate system. While system is pumped out and pressures equalized strip out the HG gas solenoid vav, either replace or re-kit the internals.

[charlie patt]

what is your bottle pressure useually on these they will take 2 kilo without running ,the 410 unit i have never seen all the atlas we have done is 404 or 134/ have you carried out a flow check just to sea if any blockages and what is the run amps when on please advise ta charlie

[paul441]

Thanks guys for your response, i found the problem why couldnt get full charge in.
the hbpv valve had open circut wher it feeds from the elektronikon 2 wires 1&2 one not getting connection in 1, plug
not opening soleniod,got charge in and now running hbpv opening fan coming in ect and a dp of 2.6
thanks for ur help