IET logo
 
IET
Decrease font size
Increase font size
Topic Title: 240v damaging equipment
Topic Summary:
Created On: 29 January 2013 07:52 PM
Status: Post and Reply
Linear : Threading : Single : Branch
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 29 January 2013 07:52 PM
User is offline View Users Profile Print this message



jamesrussell

Posts: 81
Joined: 11 January 2008

As we all know our supply varies around 240 but I have a friend who imports guitar amplifiers from america and has shown me one with a 230 mains input. He has asked me can this have effected the running of the valves as he has had to send one of these units back for repair.
I have wondered whether anybody else has had similar problems as a lot of equipment now is designed to meet the latest European !"£$$ legislation re lowering our voltage to 230 and the rest of Europe up to 230 so potentially this new equipment could be getting 250v any comments out there
 29 January 2013 08:14 PM
User is offline View Users Profile Print this message



impvan

Posts: 705
Joined: 07 September 2005

I would expect modern equipment to have the valve heater chain run from a regulated power supply, and so reasonably immune to supply variations.. But you said american, so expect little electrical progress since the days of Franklin...
 29 January 2013 08:32 PM
User is offline View Users Profile Print this message



jamesrussell

Posts: 81
Joined: 11 January 2008

yes i am almost certain its run off mains tx and if memory serves me well I looked at a marshall amp the other month and that also ran from tx but just wondering if some of our normal equipment ie kettles etc could be more unreliable due to our supply
 29 January 2013 09:01 PM
User is offline View Users Profile Print this message


Avatar for rocknroll.
rocknroll

Posts: 8808
Joined: 03 October 2005

I have four, two of which are tube amps of N American origin, the Marshall generally has 120/240V switch on it, most good amps from US have the selector switch, I know of Eden, Epifani, SWR and many others have this facility, they work fine in the UK and Europe.

There is one thing that can be important, if the amp has been configured for the N American market 120V then the fuse is 4 Amp and when selected to 240V you may need to change it for a 2 Amp, this is normally done by the 'middle man' but if your colleague is buying direct this may be omitted.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 29 January 2013 at 10:01 PM by rocknroll
 29 January 2013 09:18 PM
User is offline View Users Profile Print this message



AJJewsbury

Posts: 10963
Joined: 13 August 2003

There is one thing that can be important, if the amp has been configured for the N American market 120V then the fuse is 2 Amp and when selected to 240V you may need to change it for a 4 Amp

That's curious - normally a doubling of the supply voltage would mean a halving of the current for the same delivered power.
- Andy.
 29 January 2013 09:28 PM
User is offline View Users Profile Print this message



jamesrussell

Posts: 81
Joined: 11 January 2008

these amps are not labled for our old 240 but are new 230v european spec so they are running higher than designed on our mains most of my friends amps he has checked are labled 240 but has anyone else got any equipment labled 230
 29 January 2013 09:54 PM
User is offline View Users Profile Print this message



AJJewsbury

Posts: 10963
Joined: 13 August 2003

these amps are not labled for our old 240 but are new 230v european spec so they are running higher than designed on our mains most of my friends amps he has checked are labled 240 but has anyone else got any equipment labled 230

Bear in mind that "230V" and "240V" are "nominal" - i.e. they're just convenient 'names' for a range of voltages.

"240V" was really 240V +/- 6% - i.e. between 225.6V and 254.4V, while
"230V" is 230V +10% -6% - i.e. between 216.2V and 253V - not hugely different.

- the actual voltage under both systems varies considerably - not just with location, but with connected loads. If you or next door had off-peak electric heating then expect the voltage to drop overnight or during the afternoon boost. If you happen to share a main with an industrial estate, then it can easily knock on the 253V limit out-of-hours (as several of my work UPSs insist on bringing to my attention).

For all practical purposes equipment properly designed for European "230V" should be absolutely fine with what used to be called a 240V supply.

- Andy.
 29 January 2013 10:02 PM
User is offline View Users Profile Print this message


Avatar for rocknroll.
rocknroll

Posts: 8808
Joined: 03 October 2005

Simple typing error, now corrected.

Whether they say 230 or 240 still works fine in UK.

If only you knew some of the 'real' not theoretical extreme voltage variations this sort of equipment works under in venues and outdoor events and the place keeps on 'rocking'

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 29 January 2013 at 10:10 PM by rocknroll
 29 January 2013 10:52 PM
User is offline View Users Profile Print this message



unshockable

Posts: 828
Joined: 18 May 2007

Originally posted by: rocknroll

Simple typing error, now corrected. [IMG][/IMG]



Whether they say 230 or 240 still works fine in UK.



If only you knew some of the 'real' not theoretical extreme voltage variations this sort of equipment works under in venues and outdoor events and the place keeps on 'rocking' [IMG][/IMG][IMG][/IMG]

regards


But surely the American 240V is actually 2 phase center tapped?

Won't this possibly mean that components designed for 120V RMS wrt earth (+-200V peak) will be subjected to 380V peak or so, wrt earth?

This could lead to failure?

Simon

http://wiki.answers.com/Q/How_...breaker_is_120V


And another to make my point.

Edited: 29 January 2013 at 11:20 PM by unshockable
 29 January 2013 11:31 PM
User is offline View Users Profile Print this message



alancapon

Posts: 5698
Joined: 27 December 2005

Originally posted by: jamesrussell
these amps are not labled for our old 240 but are new 230v european spec so they are running higher than designed on our mains most of my friends amps he has checked are labled 240 but has anyone else got any equipment labled 230

If they are, then they have not been constructed for the UK market. As Andy correctly points out, the equipment must work satisfactorily at the top and bottom of the UK voltage range, which is 216.2V to 253V. You also need to remember that the UK has a frequency of 50Hz, whereas America uses 60Hz, which may have implications on the construction of the transformers.

Regards,

Alan.
 29 January 2013 11:32 PM
User is offline View Users Profile Print this message


Avatar for rocknroll.
rocknroll

Posts: 8808
Joined: 03 October 2005

But surely the American 240V is actually 2 phase center tapped?


I was referring to the US amps that have a selector switch on them, for this purpose I will give you a couple of configurations;

One has two positions 100/120V and 220/240V

The other a Eden has three positions; 100/120V, 220V and 230/240V

The other two are the same as the first one and all of the amps are set on the 220/240V position with the locking screw and have caused no problems here and across the channel.

Either the amp is configured for the US in which case it will go bang with a lot of smoke, I actually saw that when a US Marine Bandsman guitarist plugged an amp into a UK supply via an adaptor at the Riviera Centre in Torquay and needed to borrow one of our amps, or the unit in question has gone faulty.

Just a point you can use a US configured amp in the UK but you need a step down transformer, the 50/60Hz does not make any difference in these cases it still works fine you might get a bit more hum but you can often clear that.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 29 January 2013 at 11:41 PM by rocknroll
Statistics

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2014 FuseTalk Inc. All rights reserved.