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Q: Maximum DC voltage for domestics usage ( No Answer,   5 Comments )
Subject: Maximum DC voltage for domestics usage
Category: Science > Technology
Asked by: psofmind-ga
List Price: $10.00
Posted: 17 May 2006 21:39 PDT
Expires: 16 Jun 2006 21:39 PDT
Question ID: 729939
Maximum DC voltage which is restricted for domestics usage
by stafty standard like UL and CE ?
And exact provision of the stafty standard? 
I am designing DC appliance for home appliance.
There is no answer at this time.

Subject: Re: Maximum DC voltage for domestics usage
From: ro11-ga on 18 May 2006 04:53 PDT

"Circuits with voltages above 60 V DC or 42.2 V AC peak
between any two conductors, or between any one such
conductor and earth, stored energy levels of 20 J or more or
available continuous power levels of 240 VA or more are
considered to be hazardous according to IEC/EN 60950."
Subject: Re: Maximum DC voltage for domestics usage
From: psofmind-ga on 18 May 2006 22:20 PDT
I am considering 380DC voltage/64W motor for home appliance.
And I want to check if it is okey for home appliance.
To sell the motor, I should get CE or UL approval.
So, I should know the restriction of stafty standard.
Subject: Re: Maximum DC voltage for domestics usage
From: neilzero-ga on 21 May 2006 19:41 PDT
There are many presidents for much higher voltage. 40 years ago, 21
inch TV sets used as much as 25,000 volts dc at 20 watts. These TV
produced soft Xrays, so a redesign was necessary. Even today TV are
being sold with more than 15,000 volts dc, and computer monitors, copy
machines, bug zappers, electric fences have voltages almost that high
at several watts. Worse the horizontal amplifier tube of those 40 year
old TV sets had pulses to 5000 volts at as much as 50 watts. These
produced horrible burns and sometimes death.
I have no idea how difficult it will be to get UL or other approval
for 380 volts dc. May I suggest that less than 60 volts dc should be
practical for a 64 watt dc motor. 300 watts at 24 volts dc is quite
standard for electric scooters and power wheel chairs.  Neil
Subject: Re: Maximum DC voltage for domestics usage
From: farhadabdolian-ga on 22 May 2006 03:34 PDT
Any exectrical equipment must be UL approved if you are planing to
sell it to cosnumers in the US, the same goes for the EU and CE

Even if your device has an internal high DC voltage, you must get a UL
approval for all the parts of your device, as well as aproval for the
complete device.

There are no exception to this as far as I can say,

best regards,
Subject: Re: Maximum DC voltage for domestics usage
From: terran-ga on 06 Sep 2006 22:35 PDT
if you design the motor for tools, you shall refer to IEC60745 which
for CB approval and EN60745 for CE mark, and if you design it for
appliance for house hold in dometic area, you shall make the end
product comply with iec60335 or en60335, they have part one and part
two, part one is for general use and part 2 is for special end
product. in most all standard, there contain some conception like
protect against electric shock, thermal hazard, mechanical hazard,
chemical hazard..., when you design your product, you shall conside
the fuse , the material of enclosure, the PCB, the plug and cold, the
thermal link, the switch, and other critical components shall have
approved by like VDE , TUV, UL OR other third labs. I think it is
better for appliance which use DC and load is motor , because you can
use PWM to control the MOTOR easily. I hope it will help your design
and approval .

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