View Full Version : Gah

11-08-2014, 03:42 PM
Anyone had probs with Excalibur units seizing up standby compressors?

11-08-2014, 03:53 PM
Yes but due to poor install procedures

11-08-2014, 09:23 PM
Yes but due to poor install procedures

Cheers for that, sounds like you have experienced it, maybe you could enlighten me ? It would be appreciated

11-08-2014, 11:17 PM
Oil levels need to be adjusted I have two customers who have had failures in less than one month both of th e m had the units fitted at the same supplier,and the GAH engineer informed them that shortage of oil was the cause.

12-08-2014, 12:05 PM
Ok , yes been there, reduced oil added when new comp fitted to allow for residual oil , then added extra on next comp, to no avail, both times recommend suction filter was fitted ,complete system was cleaned out by gah , also to no avail, another comp fitted without hg defrost, no good either, swopped from 404 to 134, yes you guessed it, seized comp very interesting problem.

charlie patt
12-08-2014, 08:06 PM
are u fitting seltecs or q comps? is there any oil left in the comps that seize and does it have the correct size pulley on electric motor? one issue i have had recentley was on a 24 volt version the dropper putting out only 16 volts just enough to bring contactor in but not enough volts to spin those condensor fans quickly enough also never fit a comp when seizure occured without suction filter u will be back time and time again

12-08-2014, 08:36 PM
All comps were supplied by gah as the suction filters and driers
As for the low voltage havnt checked that but the pressures were fine with 28 degs ambient so con fans were doing their job,incidentally, were the suction filters are fitted is a bit stupid as they are between the LP switch and the comp so as it chokes their is no LP protection for the comp , am trying a couple of experiments at mo, in view of the history am not over hopeful !

12-08-2014, 08:59 PM
Cleaning a system is a very long task and no shortcuts,surprised that the whole system was not replaced if it's as bad as you make out,changing from 404 to 134 will make no difference to a contaminated system don't understand the logic in that?,What type of truck/ van is it on does it have a speed reduction clutch fitted to the road compressor the lp will still operate if the suction filter blocks it would only be the same as having a service shut off valve mounted downwind you close that the pressure drops lp cuts unit out,think I would examine that oil again to see if it's going grey! Asap

13-08-2014, 07:06 AM
The change from 404 to 134 is apparently done quite often by gah
If problems are encountered and the box is not required for freeze they must be unsure if it is contamination and want to reduce the load on the comp
On stripping the last comp the oil carried no apparent metalic residue and was surprisingly clean, yep fine on shut off valve on high side shutting system down on LP , but with a blocked filter between LP switch and comp suction twill keep running till destruction ,
I am thinking maybe it's lazy oil and migrates to an obscure region of the system every now and then for a rest !

13-08-2014, 02:14 PM
Ok put a fitting close to the compressor to adapt an lp, guess there is no suction filter on supply to standby compressor

charlie patt
13-08-2014, 07:56 PM
if your suction filter is blocking that bad u have to flush system and like cad says lp will trip as far as gah changing 404 to 134 it dont happen 404 has a better oil recovery pressures are less on 134 but u need to change pressure switches power valve etc etc we need more facts i pressume its a tm comp? is the unit a heat model and i pressume u are measureing oil in comp not just fitting it? out of gah i have had comps with 250 cc oil in far far to much u will seize it in ahr if u had a oil issue comps would be dry and engine comp gets its first my advise is to start from fresh i personally run all chillers on 68 oil freezers on 32 unless hermetic comps hubbards on 48 check ur cages flush it remove both comps and oil as should be and check ur superheat/ also fit temp sensor on body of comp when testing if it gets warmer than 87 dc on body its seizing if it needs flushing remove all ur check valves cage and flush forever suction filter on stby and engine main drier and start again if u cant nail a gah start again and if u have trouble with a excalibur dont look at a fs7

13-08-2014, 08:45 PM
Wow... Thanks for reply The suction filter is not blocking I added the comment about the position of the filter in relation to the LP switch as fitted by gah as not satisfactory in my opinion,( I still don't see how you can say it will cut out on LP if the suction filter gets blocked) as after 5 compressors were fitted I decided to have a look, I have fitted a used sby comp and used rl68 check valves were ok a body temp test gave a max of 67dc , and gah have changed 404 to 134 c/w
Valve & power head etc, as for not being able to nail an Excalibur this Excalibur has had what should be the most knowledgeable engineers putting it beyond economical repair , we have an old super sabre that has given little problems, indeed I fitted a comp on it 7 years ago and it's still a good unit appart from the hydraulics , but it will be going to the scrap heap this year as the wagon is falling to bits, our others in the fleet are xarios, supras and tk ts (26) never had anything like this before, I guess an fs7 is another gah? If so no chance of me putting a manifold near one ,would never buy one! Cheers for your comments

charlie patt
13-08-2014, 09:34 PM
unit thats had five comps has had poor engineers some one aint doing there job right full stop sometimes its time limitations sometimes its ignorance..... item 7 i have taken as suction filter blocked? if suction filter blocks with debris this limits pressure via system and trips lp lp switch is in suitable position to work on stby and engine if u are just killing stby comps and not engine comps its a speed issue with spin speed of comp u ask cad how many engine comps to stby he fits ten to one cad? excaliburs are in my humble opinion a cracking unit but like all stuff sometimes they need love and if u are ripping it of to i will lberate it from u ta charlie

14-08-2014, 12:37 AM
Something wrong here I can hear alarm bells ringing!!!this unit should have been scaring people when the second one failed,is this unit running on standby in an oven? Is the condenser clean you must have airflow over this comp to cool it,glad it's not on my patch but think. I would take it on just to nail it.

14-08-2014, 07:27 AM
Thanks guys, liberate it ? Haha Naw!! There is nothing made that's not fixable, yes the beast does in sby not road comps sby comp rpm is spot on so not over reving , our units don't get much use on road compared to sby and only in short hops, alarm bells ring for me when manufacturers want to take it off hg df and change the gas early on in the comp demise chain, sorry if my mentioning the suction filter implied it was blocked, it wasn't, it was purely my observation that in my opinion
LP switch..... Suction filter.......compressor
should not be the order of things and I still hold that opinion
And should this filter become restricted or worse the return flow of life to the comp would be reduced or stopped yet the LP switch would still be in the residual pressure and not shut the unit down, assuming the trip pressure of their switches isn't surprisingly high. road comp would of course still be protected.
if my choice had to be gah it would be a sabre without the hydraulics, thankfully it's not , think I may employ some punkawallers for this unit !
Yes con matrix is Crystal clear and we don't park it in an oven, nor do we transport hot bricks straight from the kiln
Seriously guys thanks for your time and input to a brain that's loosing it's edge ?

Mick Carroll
19-08-2014, 09:16 PM
Is this unit 3phase, if so I reduced the motor pulley diameter on a few of them years ago to slow down comp speed as I had a few of them go

20-08-2014, 02:40 PM
Thanks Mick, I have solved the problem now permanently!!
Fitted a xarios 600, but will bear that in mind as unfortunately have two more in the fleet, think I will do just that before next summer, cheers

21-08-2014, 01:39 AM
Gah units remind me of something made in a garden shed ,but they work to an extent but you do get what you pay for with them and Hubbard.

21-08-2014, 08:06 AM
Thanks cad, yes all true, but think I would disown one if it had come out of my garden shed !!