View Full Version : Voltage monitor in Transporter - Accurate ???

Mad Mr H
2008-08-03, 14:21
Im curious......

The other day my Transported had "Over Voltage" on the left hand display.

A power cycle and all was fine.

Under "Status" in the "settings" menu from Squeezecenter I have now seen 246 to 255 volts, the UK supply is meant to be 230VAC.

So could anyone else check what they get ??? against what their local voltage should be ???

Many thanks.


2008-08-03, 20:24
I remember reading that it's not supposed to be particularly accurate, just enough so it can figure out the voltage switching. Having said that, mine is reading 120v which is correct.

2008-08-03, 20:32
radish wrote:
> mine is reading 120v which is correct.

And how to you know that 120v is correct and not 117v or 122v?
Have you sent in your Fluke meter for calibration?

I know I have not, I didn't know that they can be calibrated or should
be, until a wisehat EE called me out on it.

In my house, the power company voltage varies all over the map. I don't
trust it to be more than plus or minus 5V on a good day and 10V on a bad

Pat Farrell

2008-08-04, 06:02
Actually the mains voltage is only a nominal voltage, and regulations allow for a percentage variation around that nominal voltage. If you read the quote below from Wikipedia, you will see that the UK is still generally outputing 240V, despite what the Daily Mail might like to say.

In my place I normally get about 240V during the day, and up to 250V at night - according to the TP.

quote from Wiki:
"Following voltage harmonization all electricity supply within the European Union is now nominally 230 V ± 10% at 50 Hz [1]. For a transition period (1995–2008), countries who previously used 220 V will use a narrower asymmetric tolerance range of 230 V +6% −10% and those (like the UK) who previously used 240 V use now 230 V +10% −6%[2]. Note that no change in voltage is required by either system as both 220V and 240V fall within the lower 230 V tolerance bands (230 V ±6%). In practice this means that countries such as the UK that previously supplied 240 V continue to do so, and those that previously supplied 220 V continue to do so. However equipment should be designed to accept any voltages within the specified range.

In the United States[3] and Canada[4], national standards specify that the nominal voltage at the source should be 120 V and allow a range of 114 to 126 V (-5% to +5%). Historically 110, 115 and 117 volts have been used at different times and places in North America.[citation needed] Main power is sometimes spoken of as “one-ten”; however, 120 is the nominal voltage."


for the whole article.

2008-08-04, 17:46
radish wrote:
> mine is reading 120v which is correct.

And how to you know that 120v is correct and not 117v or 122v?
Have you sent in your Fluke meter for calibration?

By "correct" I meant "expected", unlike the OP's which was showing figures which look outside of any reasonable tolerance.

Mark Lanctot
2008-08-06, 08:47
The OP did have a rather odd figure. You'd expect voltages in the summer to be a little under nominal.

At my previous house, TP reported voltages usually at 122 V. Here, it seems to be locked steady at 117 V.

The utility here was experimenting with voltage reduction in previous summers when high load hit due to hot weather, but it hasn't been particularly hot here this year and I don't believe they are currently reducing voltage.

I haven't double-checked TP against a meter though, and the meter would definitely not be calibrated - it's a Radio Shack special, although a good midrange one.

2008-08-06, 09:47
this is a software bug - I am looking into it

Mad Mr H
2008-09-21, 10:57
Hi, Thank you.

PS - Im in the UK so thats why mine is in the 240 ish range and not 120 !!!

Im sure some of you guessed this.

Any news on a resolve for this? Mine has not gone into "safe mode" again.

Just in case its any help

current info

Firmware: 59

Voltage: 247

I can measure the actual mains voltage if this helps (yes calibrated)

Im an AV engineer by trade so have many items of test equipment that the average person does not usually own......


Teus de Jong
2008-09-21, 11:14
You should upgrade to SqueezeCenter 7.2 with transporter firmware version 62. In that version the bug Sean mentions is fixed.