dryer fault

[paul441]

Hi guys

Just after some advice regarding dryer fault,i have a deltech smard dryer which never worked on , anyway put new comp on this unit and it ran ok for 2 wks but it is now showing a alarm fault (high evap temp) this unit has 12kg r404.
just looking for some help to point me in right direction as to what my faut could be.

cheers

[Tradewinds]

Need more info Paul.
Is the compressor still running?
Does it have a leak
Did you pull a 2 torr vacuum on the system before you charged it

12kg of R404a, so you must be a CAT 1 engineer.

If you can tell us what you did when you changed the compressor and provide more info then we may be able to help you some more

[paul441]

Hi
Yes comp still running fan etc,i am not cat 1 engineer have being in this job for about 1 year working on atlas copco dryers small stuff, learning the operation of dryers buy have not worked on anything like this deltec smard dryer,
when fit comp pressure tested and then put on vac (not 2 torr) charged system 12kg r404 and run unit which seemed ok showing goog dp,but last week unit went into alarm high evap temp ,dp and temp indicator right up on controller, am struggling now to rectifiy fault due to my lack of experience as i say not being in game long,
condensation on comp what would that be.
anyway cheers for your reply and would apprciate any more help.

[glenn1340]

did you change the filter dryer when to fitted the new comp. Just an idea before you go in deep on the dryer, is the problem elsewhere on the system as high ambient temps we`ve been having the last few weeks could be the problem. Are the air compressors runiing hot and delivering high temperature into the dryer, is the plant room room very hot, is the condensor clear on the dryer. Many a time I`ve had this problem omly to find the dryer was working on its full capacity and the air usage went up due extra machinery bieng installed with no though given to the air treatment.

[taz24]

.

I read this post wrong when I first read it.
I thought you were talking about the dryer inside the system (Liquid line dryer),
but you are talking about an air dryer itself.

There are lots of reasons why this could happen and you need to go back to the basics.

Why did the original comp fail?
Are the heat exchangers (filters) free of dirt?
When you changed the comp did you replace the electrics?
Was there contamination inside the system?
Did you replace the refrigerant with new?
Did you replace the old liquid dryer for new?
Did you pressure test with OFN?
Did you vac down the system to the correct levels?

Answer those and then tell us what the discharge and suction
pressures / temps are.

But as tradewinds points out you need to be properly qualified to work
on refrigeration systems and if you don't have the qualifications or working
under supervision then you may be contravening the regulations somwhere.

All the best.

taz

.

[taz24]

am struggling now to rectifiy fault due to my lack of experience as i say not being in game long,
condensation on comp what would that be.
anyway cheers for your reply and would apprciate any more help.



You need to understand the principles of fridge to know what that means.

Your system is 2 large heat exchangers working in a ballenced system.

The heat it absorbs at one side it rejects at the other.

Moisture always goes to the cold areas so if you pass warm moist air over a cold surface
you remove the moisture from that air. That is the evaporator side of the system (low pressure side).

To create this low pressure / low tempreture interface you have to boil refrigerant at
a tempreture lower than the air passing over it (this happens inside the evaporator).

If the evaporator runs too low in pressure ? tempreture then you could get condensation (as you call it)
on the suction pipe back to the comp.

If there is too much liquid it could cause it.
If the evaporator is dirty it will not exchange the heat correctly so the refrigerant will not all
boil off and some of the excess may pass back to the comp.

Repairing faults in refrigeration is not just about replacing parts.
You need to understand why the original part failed in the first place.

There could be as many as 10 reasons why this happens and to find the fault, you need to
be able to use your gauges and thermomiters as tools to direct you to the reason.

All the best

taz.

[Tradewinds]

Hi Paul,
Sorry mate but I have to say it (all in the nicest possible way). You have just announced on a public domain that you are working on a system with 12Kg of R404a without being quailified to C&G 2079 Cat 1. Hopefully you are qualified with CITB.
If not then there are plenty of training centres around so please go and get yourself qualified before the 4th July as you may already be working illegally. Penalties can be up to a maximum of 5K if tried in a magistrates court or unlimited if it gets to a crown court.

[Magoo]

I live on the other side of the world, can you explain the CG 2079 cat 1.

[taz24]

I live on the other side of the world, can you explain the CG 2079 cat 1.

Yes..

In the UK we have to have one of two qualifications to prove we are
competant to work with refrigerants.

One is a City & Guilds qualification 2079.
The other ia a Construction Industry Training Board (CITB) qual - J 11.

This meets a European agreement for all our Nations to be proved able to
at least a very basic level.

It is not a Refrigeration compentancy qualification realy, it only proves the
person is competant to work with refrigerants and knows somthing about
their impact on the environment.

All the best

taz

.

[Magoo]

Thanks Taz