[Amps] Power cord to use when converting AL-80B to 240 volts?

Will Matney craxd1 at verizon.net
Sun Oct 2 18:23:44 EDT 2005


I have no problem about the current rating as I know it's 1/2 at 120 Vac. I just dont like to run a white wire as a hot wire or especially a ground. I do remember though about re-coloring the wire as you mentioned but I don't know if that is permissable now either. It would be better to do that though than nothing at all. If you use a four wire cord with a three wire plug, you just dont use the white in it unless it's needed. Most just cut it off even with the cable sheath. Looks like they'd make a three wire colored black black green or black red green but they dont that I know of. Plus that still leaves the necessary grounding for safety.


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On 10/2/05 at 6:13 PM TexasRF at aol.com wrote:
A common workaround is to cover the white wire end with black tape or heat shrink. This was allowed in the NEC book 25 years ago; not sure about today.

The use of four wires can be a problem if the existing 240vac outlet has only three wires. If three wires worked when the amplifier was manufactured why can't they work today? If rewiring the amplifier and cord for 240vac cuts the primary current in half then the power loss is cut into one fourth. What is wrong with that? 

73/k5gw

In a message dated 10/2/2005 4:11:56 P.M. Central Standard Time, craxd1 at verizon.net writes:
Bill,

I can tell you that the NEC sure does frown on using white as a hot. There's only one permissible way they allow it and that is for the switch leg on a wall controlling an overhead lamp. There you run the hot to the white of the switch and bring it's black back to the black of the lamp. Using white for a hot in a power cord is the same as using the green as laid out by the NEC. Most pigtails have no color code like the grey ones but mark the outside with some ridges for the neutral. Then when using them your supposed to ad an external ground wire from the chassis to ground. That's not the way I spell it out but the way the NEC does. The wire don't know what color it is, but when someone mistakes a white for a hot, it could cause harm if they didn't know it was tied to hot.

Best,

Will


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On 10/2/05 at 4:53 PM Bill Coleman  N2BC wrote:

>It is quite OK to use the white on one of the phases in a 240V hookup. 
>It 
>is never OK  to use green to anything other than ground.
>
>Most modern amps have no need for neutral when wired for 240V.  If neutral 
>is indeed needed for something inside that is 120V only then the only way
>is 
>to use a 4-wire cord.
>
>Bill  N2BC
>----- Original Message ----- 
>From: "Will Matney" <craxd1 at verizon.net>
>To: <amps at contesting.com>
>Sent: Sunday, October 02, 2005 3:58 PM
>Subject: Re: [Amps] Power cord to use when converting AL-80B to 240 volts?
>
>
>> Colin,
>>
>> That's true as long as the cable is rated for 220 Vac, and you don't
>want 
>> to add a ground with the neutral. To do it right, I'd want a three wire 
>> with ground cord. Most 120 Vac cords only have three wires. To use a 120 
>> Vac cord on 220, you'd have to use the ground wire for the neutral which 
>> most of the time is a green wire. That is if you intend on using
>anything 
>> on the 120 Vac line. Plus your using a white wire as a hot. The correct 
>> way is have a black and red wire as hot, white as the neutral, and green 
>> to ground.
>>
>> Best,
>>
>> Will
>>
>> *********** REPLY SEPARATOR  ***********
>>
>> On 10/2/05 at 12:47 PM k7fm wrote:
>>
>>>If the mains cable for the amp is designed for 120 volts, it will handle
>>>240
>>>volts.  The current is 1/2 at 240 volts, so you could actually make the
>>>cable smaller.
>>>
>>>Regarding voltage rating, each wire is 120 volts to ground, so the
>>>insulation need be no higher than for 120 volts (insulation between wires
>>>is
>>>doubled because both wires are insulated.
>>>
>>>Colin  K7FM
>>>
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>>>Amps mailing list
>>>Amps at contesting.com
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>>
>>
>>
>> _______________________________________________
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>>



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