Keep in mind that there are usually not "2 phases" anywhere in residential
service. It is single-phase 120/240v.
You can say "2 hots" or "2 legs" but you can't say "2 phases" because they
do not have any strange timing relationship, only 180 degrees.
The power company takes a single leg (phase) from their system and runs it
into a transformer. The transformer has a 240v winding, and they connect
the neutral to the center-tap.
If you actually had "2 phases", you would end up with 208v across the 2
hots, not 240.
-Phil
----- Original Message -----
From: "Cor van de Water" <
[email protected]>
To: "Electric Vehicle Discussion List" <
[email protected]>;
<
[email protected]>
Sent: Monday, October 29, 2007 1:51 PM
Subject: Re: [EVDL] Electrical Standards
> If you want to check if it is at your side or the
> power company's then you can check either different
> outlets that attach to adjacent breakers (which should
> have alternating connections to each of the two phases
> of 120V that make up the 240V service).
>
> If you measure 140V from one outlet and 100V from another
> then you will need to open up your service panel and
> measure the voltage of both phases coming into your
> service panel, if you still see 140V and 100V there,
> coming from the meter and relative to neutral then it
> is likely that the neutral is disconnected somewhere
> upstream and the *load* balance between the two legs of
> phase - neutral and neutral - other phase is what
> determines the voltage.
> If you switch on a heavy duty 120V appliance like a
> microwave or garage opener, you may see the voltage shift
> between the two phases.
> In that case: immediately call the power company to send
> someone out or else you can experience broken appliances
> and lights from over- or undervoltage.
>
> Normally there is at least 10% tolerance in the specs of
> line voltages, though long lines and heavy load can
> occasionally cause the voltage to go beyond that range.
> That is the reason most devices will work on only 90V AC
> but not many expect a voltage over 132V, unless they can
> work on 230V without reconfiguation, then they usually
> go all the way to 265V (240V + 10%)
>
> Cor van de Water
> Systems Architect
> Proxim Wireless Corporation http://www.proxim.com
> Email:
[email protected] Private: http://www.cvandewater.com
> Skype: cor_van_de_water IM:
[email protected]
> Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
> Fax: +1 408 731 3675 eFAX: +31-87-784-1130
> Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb
>
> -----Original Message-----
> From:
[email protected] [mailto:
[email protected]] On
> Behalf Of (-Phil-)
> Sent: Monday, October 29, 2007 1:38 PM
> To:
[email protected]
> Subject: Re: [EVDL] Electrical Standards
>
> 157v is WAY out of spec!
>
> That is a dangerous condition! I suspect a floating neutral. I'd call
> the
> power company ASAP!
>
> Anything within 5% of 120 is considered in spec. If it's over 127v or
> under 113v it's out of spec, and you can call the power company.
>
> If the power company is at fault delivering out of tolerance voltage, they
> are liable for repairs to your appliances!
>
> In your case though, my guess is a floating neutral, which could be a
> problem on your side, not the power companies. Anything up to the meter
> is their responsibility, anything after it is yours.
>
> -Phil
> ----- Original Message -----
> From: <
[email protected]>
> To: "Electric Vehicle Discussion List" <
[email protected]>
> Sent: Monday, October 29, 2007 12:59 PM
> Subject: Re: [EVDL] Electrical Standards
>
>
>>
>> [This might be off topic... or it might help people understand
>> electricity better]
>>
>> (-Phil-) wrote:
>>> Funny this discussion of standards, when most people still call US
>>> standard
>>> voltage 110v when it's been 120v for over a half of a century.
>> ...
>>> Here in the US, we can generally only expect 1.8kw, (or 1.65kw for all
>>> you
>>> 110'ers) although most newer circuits deliver more, even if that's all
>>> the
>>> outlet is technically rated for.
>>
>> I was getting 157v out of a 20-amp, 125v circuit the other day. If
>> there is a nominal range (and I have seen 110-120 out of a 15-amp, 120v
>> circuit and consider that 'nominal'), is 157v in it or out of it for
>> this circuit?
>>
>> I'm wondering if voltage surges and fluctuations could be responsible
>> for the remarkably high failure rate of light bulbs in my house (even
>> well-rated Sylvania CFLs, which I've been slowly converting to).
>>
>> To try and yank this back to EVs: does voltage variability in the home
>> impact how the charger handles charging?
>>
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