Are close to the other Embassys?
I know that doesn't help, but I couldn't help myself.
Hi All,
Had a visit From a Frequency Engineer from Ofcom, We apparantly have an interference source on one of our roofs.
The roof in question has 2 Air Handling units each with 2 supply and extract fan Inverters and a Large number of Condenser units, each serving a number of split units.
The Interference has been described as being intermittant in nature, sometimes not occuring for days and only lasting for a few minutes, sometimes Lasting for over 30 minutes.
The Interference has been occurring since November last year and can occur at any time of day or night. The occasions of interference have started to become less frequent and were almost completely absent between 25/12/2010 and 02/01/2011.
I believe the source of the Interference may be one of the condensor units operating in heatpump mode. This theory would tie in with the recorded pattern of Interference, More frequent in cold weather, Not occurring during the christmas holiday period.
We stood on the roof for a couple of hours without any sign of the Interference, The Frequency engineer will return next week to try again to locate the problem and at that time will we run the units to try to cause a re-occurance of the problem.
Any thoughts or prior experience of this kind of issue?
Are close to the other Embassys?
I know that doesn't help, but I couldn't help myself.
You have got to learn from other people's mistakes! Because God knows you don't live long enough to make them all yourself !!!!!!!!
several years back it was an issue in smaller equipment, the fix was like a $3.00 part from radio shack
maybe someone else will chime in and remember better than i
It`s better to be silent and thought the fool; than speak and remove all doubt.
I would guess RFI could be coming from the Inverters in AHU's.
VFD's have been known to cause problems with AM radios in the vicinity.
Might want to consult an electrical engineer, if this is confirmed to be the source of problem.
Solution might be as simple as installing line reactors ahead of the VFD's.
Let us know what you find.
“If your work speaks for itself, don't interrupt.” ~Henry J. Kaiser
"Highly efficient equipment and LEED Bldgs are very expensive to maintain in order to keep that efficiency!" ~ Me
No, its interfering with a emergency services repeater mast.
Police, Ambulance and Fire Brigade...
We original thought it would be the AHU inverters again (occurred before and inverter was replaced) but the pattern of occurance doesn't fit. The AHU's run 24hrs a day, 7 days a week (weekly changeover).
If we find out what the cause is I'll let you know (I say If as this an intermittant problem that seems to be occurring less and less often).