Fault finding

[marc5180]

Hi guys been called to a Airedale unit tomorrow that for some reason wont even come on. Can anyone give me any fault finding tips i.e electrical. The first things you should check when the units wont start because i know on Airedales you dont get given fault codes.

[Brian_UK]

Do we know which model or type it is yet?

It may have electronic or mechanical controls.

I suppose check power, pressure switches, delay timers.

You never know it just be simply 'broke';)

[marc5180]

Do we know which model or type it is yet?

It may have electronic or mechanical controls.

I suppose check power, pressure switches, delay timers.

You never know it just be simply 'broke';)

All i know is that it has an airedale condensing unit with an indoor AHU controlled by a trend controller, with an EEV and a few solonoids. One of the engineers went to it the other day...found a leak, repaired it but he couldnt get it to come back on. I asked if he had turned the temp down on the controller but he said he couldnt get into it. So thats why im looking for help on fault finding cos the control circuit ialways seems to baffle me.

[The Viking]

Aha, it's Trend controlled, has been in alarm (fault) mode, been repaired and now not starting.

Most Trend systems will monitor alarms or faults (your LP switch for example) then, depending on the trend's setup, it will not ask for your unit to run again until the alarm been reset in the Trend.

[marc5180]

Is there normally a code to get into these trend controllers or not? its just that the other engineer had problems getting into it.

[The Viking]

BTW, to prove or dismiss this;

The Trend's outstation is only a bank of relays, you will find two terminals in the controls of your unit (remote ON/OFF, remote enabling or the like) going to the Trend (there might be others on the alarm side of things but ignore them for now) short these two terminals and your unit should start if it's the Trend holding it Off.
The above assumes that there is a "local" control in the A/C unit, otherwise there will be individual terminals for the fan, the compressor, the reversing valve and so on....

[The Viking]

Yes, there is a code.

BUT,

It's set by the commissioning engineer, so no standard codes.
If you are a registered Trend company you can call them and tell them what the time/date is on the display and they will give you a code that will work for an hour or so.

[marc5180]

OK il try this first thing tomorrow and post back tomorrow evening. Thanks for your help:D

[bobjob]

Re Fault finding

Airedales first level code is always 4648
try this to alter temperature set points etc

If it is in a computer/server room we always set everthing for auto restart after the electrical power is restored, so try just switching on at the mains isolator and it may just reboot.

If it is comfort cooling you may have to enter the Trend software to reset the air flow switch etc.

Airedale tel no is 01132391000 give them the unit type and the Unumber and they will talk you through the trend controls.

Bob

[marc5180]

Re Fault finding

Airedales first level code is always 4648
try this to alter temperature set points etc

If it is in a computer/server room we always set everthing for auto restart after the electrical power is restored, so try just switching on at the mains isolator and it may just reboot.

If it is comfort cooling you may have to enter the Trend software to reset the air flow switch etc.

Airedale tel no is 01132391000 give them the unit type and the Unumber and they will talk you through the trend controls.

Bob

Thanks for the info Bob il let you know how i get on.

[slingblade]

Hp,Lp,Oil etc.
Airedale use a latching relay for the control circuit (at fault) quite a lot on standard CU units, pull all the relays out of the holders and replace. Difficult to tell without seeing it.;)

[marc5180]

Forgot that i had posted this, iv been back today to the unit and iv posted what i found today here....


http://www.refrigeration-engineer.com/forums/showthread.php?t=8383

[Tiesse]

I appreciate that my reply may be somewhat late on this subject, but Airedale units with a Trend controller typically have a software switch (from memory, it may be switch 12) that needs user intervention following an airflow failure alarm.

If the unit has failed on airflow, the unit will not re-start without this switch setting being changed.

Also, regarding the PIN, as previously posted, Airedale's standard Trend PIN was 4648 which I think gave level 99 access (highest level). To be clear, this is a standard Trend code for Airedale units fitted with an IQ204 as it used to get a helpful mention in their manuals at the time.

If that number has changed & you have access to either a Trend System House or Trend System Integrator, you will have use of PIN of the day. To use that, you need to have the firmware version of the Trend controller & what day/date/time the controller thinks it is (not necessarily what the actual day/date/time is!). Depending on the firmware, the PIN of the day that goes with your controller is vcalid for that day, however is accurate within plus or minus 5 digits of the actual number.

You also get access to PIN of the day if you are Trend trained & hold a valid PNet card as I do.

I don't believe that Airedale now fit Trend as standard.