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Tayters
27-08-2011, 11:54 PM
On this model are the high and low alarm settings relative to the setpoint or the actual temps the alarm will go off?

I even refered to the instructions. They say the settings are absolute but other info I have says they are relative.

No fault on the coldroom other than an intermittant alarm which gets ignored as there is a separate monitoring system for that. I've only seen it happen once when working on something else. It was alarming on the high alarm but coldroom was at -18*C. I've reset the alarms for a relative setting (they were -10 and -25 before) to see what happens. Not sure why it doesn't alarm all the time though after the delay time has been reached - unless a defrost resets it?

Cheers,
Andy.

install monkey
28-08-2011, 12:02 AM
normally eliwells reset when reaching setpoint range, hi low alarms are set as threshold temperatures ie +20 for hi alarm and -28 for low temp after any programmed aarm delay,(actual temps not offset temps from setpoints) hope this helps

Grizzly
28-08-2011, 12:05 AM
They appear to be relative to the setpoint?
Read the attached it may help?
It does indeed appear as if there is no differential.
Just a simple on off alarm signal either above the alarm settings or below dependant upon whether you are compairing the high or low settings.
Good luck.
Grizzly

Tayters
28-08-2011, 12:23 AM
Hi Grizzly,

Thanks for the reply.
That's the info I've got in the van (relative to setpoint) which contradicts the info which comes with the controller (absolute values) which was in the electric panel.

Grizzly
28-08-2011, 12:45 AM
One way to confirm would be to lower the setting and observe the alarm status and operation, would it not?
Also check out the attached.
Grizzly

Tayters
28-08-2011, 10:44 AM
Hi Grizzly,

That's what I've done but the alarm does seems intermittent. I've left it over the weekend and will get a chance to recheck it on Tuesday.

Cheers,
Andy.

Grizzly
28-08-2011, 11:08 AM
Intermittent is not good, possibly one of the hardest types to pin down.
Transducer voltage, radio / aerial interference and many more!
Good Luck my friend.
Grizzly

Tayters
06-10-2011, 06:13 PM
Just to update the thread, with the alarm settings relative to the setpoint things seemed to have quietened down now.

Thanks chaps for your input,
Andy.

chillerman2006
06-10-2011, 06:25 PM
Hi Tayters

there is software/hardware available which you can set up to record side by side temps/pressures contactors position amps/volts etc etc ............you set it to take data from the units boards own inputs/outputs - digi/analogue

http://www.picotech.com/data-logging-software.html

costs a fair bit to get setup with everything first time round, but a lifesaver for intermittent faults

R's chillerman

Tayters
06-10-2011, 06:46 PM
Hi Chillerman,

Yes I've seen the Picotech stuff, looks good. Have toyed with the idea of with getting the oscilloscope for ages now. Will put it on my christmas list.

Cheers,
Andy.

al
06-10-2011, 07:27 PM
I got the pico enviromon kit, great value for what you get. Can monitor voltages, current and a multitude of temperature inputs, but fiddly to set up each time, but still good value and very good technical help.

al

Peter_1
06-10-2011, 08:00 PM
We have 2 sets of Pico and they work very well.
But it is indeed a great work to set up, so we build everything in a box and all the connectors for Thermocouple and pressure readings with fast connectors on the outside.
I can take some pictures if you want to see it.

al
06-10-2011, 08:45 PM
I'd like to see that Peter, thank you.

alec

Peter_1
06-10-2011, 10:46 PM
From a job on a Lennox chiller.
You can see on the right site of the (cheap) suitcase the connectors for temperature and thermocouples.
Under the suitcase an UPS in case of power failure (my battery from my old laptop isn't that good anymore)
I can make some pictures of the inside but that's only the ADC-16 and a TC-08 in a PU foam.
You can also see the pressure transducers and the AMP clamps and the voltage clips.

Measuring the amps remains always difficult. The ADC-16 pulses the amps at a very fast rate (milliseconds) and the reading all depends on what edge of the sinusoid you take the reading. The current is in a fact an exact copy of the ever fluctuating voltage (the current clamps you see) at a speed of 50Hz in Belgium. You can see in the current the same sinusoid as in the ever changing voltage. I - or better, my son - had to experiment with a capacitor over the voltage measurement to get better stabilized readings. Or, I was doing something wrong is of course also a possibility.

You can see the 3 way splitter on the mains in front of my laptop. We had to remove the earth in this splitter because we couldn't get rid of the noise picked up by - as far as I remember- the pressure transducers. We use 0-10V, 4-20mA and 0-5V transducers. The 0-5V are from Dixell and Carel and they are cheap.

My son also needed to increase the voltage coming from the clamps because this was to small for the ADC-16. I think- should take a look in the suitcase - he used Eliwell transformers in opposite connection. Making 220VAC with a 12VAC signal ratio if you get what I mean.

al
06-10-2011, 11:10 PM
Nice set up Peter, i never considered the readouts from the clamp meters might need tweaking! I got different clamps, would these need adjusting as well?

al

chillerman2006
07-10-2011, 05:20 PM
Hi Al

a stealth set-up....that not showing nothing but red wires

R's chillerman

simon@parker
07-10-2011, 07:23 PM
tayters i could be wrong usually am but if it just randomly alarms it could be one of the probes is failing ? they dont always go completely :)

Tayters
07-10-2011, 08:39 PM
tayters i could be wrong usually am but if it just randomly alarms it could be one of the probes is failing ? they dont always go completely :)

Alright Simon,

Not sure how random it was as the staff ignored it and I noticed it a couple of times on different occaisions when walking past the coldrooms. With it taking the alarm delay into account and resetting as the Monkey stated when reaching setpoint then some randomness might occur.

Anyway random or not since changing to a relative setting the old girl is ticketty-boo.

Cheers,
Andy.

Peter_1
07-10-2011, 08:43 PM
Ticketty-boo !!??

1. Going smoothly, doing all right. Copacetic.
2. Proceeding quickly.

This expression may have originated in Scotland, where it's the title of a popular children's song. A song called "Everything Is Tickety-Boo" was recorded by Danny Kaye as part of the film "Merry Andrew".

This expression is heard more often in Canada nowadays. May have originated in the British military. Possibly related to the Hindi expression "tickee babu", meaning "everything's alright, sir". Some people spell it "diggity boo" or "tiggity boo".
Everything is tickety-boo, tickety-boo, tickety-boo...