On Sep 17, 10:08 am, email@example.com wrote:
They can, if the customer uses a 4-wire connection. Otherwise, any
120V stuff in the dryer is connected to ground and there will be (a
lot of) leakage. 3-Wire (hot, hot, ground) used to be code, but now 4-
wire connections (hot-hot-neutral-ground) are required where any 120V
circuits are used. The 3-wire connections are grandfathered for
In the context of the discussion, clearly it's a gas dryer we're
talking about that uses 120V. But broadening the discussion, why
does there have to be any 120V "stuff" in a dryer, including a 240V
electric one? I see you're point regarding backward compatibility to
an existing 3 wire dryer circuit. But in any dryer there is a heating
element if it's an electric one, a motor, and some control
circuitry. I can design all of that using just 240V. The only thing
I can think of that would ordinarily be a 120v load would be a light
inside the dryer. But it would seem someone must make a 240V
appliance bulb, no?
On Sep 17, 2:51 pm, firstname.lastname@example.org wrote:
Bulb, "I'm done" Buzzer, Timer/Control, LEDs, Liquid Crystal display,
things that go 'beep" when you turn the knob, etc.
While all of them can be implemented with 240V, I'll bet it's cheaper
to design and implement for 120V and then use the same circuity for
both gas and electric.
You gotta have 120V dryers for those of us who use gas and don't have
240V in the laundry area.
Most of the stuff on that list, ie LEDs, display, beepers, etc aren't
powered by 240V or 120V anyway. You have a transformer that powers
them, microprocessor boards, etc. So, if it;s a common design you
seek, you could have the same design for 120V gas and 240V electric,
just substitute a different transformer. Or use a transformer with
multiple taps that would support either. However, I think the
design differences between a gas dryer and an electric one are so
substantial that you would have so many other design differences that
it would render the point moot anyway.
On Fri, 17 Sep 2010 18:37:09 -0700 (PDT), email@example.com wrote:
With a switching power supply you wouldn't even need that. However, there are
still basic models out there.
No, they really aren't all that different. Were I to design one of these I'd
make every attempt to make the controls identical. This reduces costs of
engineering, manufacturing, and inventory (all the way to the consumer). We
make several products with the exact same hardware. We'd certainly do it with
products that are as close to each other as gas/electric dryers.
| If they're in proper working condition, there shouldn't be any. This is also
| Wayne's point, at least in the US, the manufacturers are responsible for
| building their stuff to the latest safety standards, so they will work
| reliably with gfci protection
I recently bought an old house with 120V fused-neutral (well, they had
been sort of bypassed) service and a mixture of old BX (no ground ribbon)
and various vintages of NM wiring. The service lines blew down right
before I bought it and the section with the service entrance was going
to be replaced anyway, so the contractor ordered a temporary service
instead of trying to get the antique reconnected.
I wanted power in the house and the new panels wouldn't be in for a few
weeks so I installed an isolated neutral bar in the old fuse box, separated
ground/neutral, and plugged the whole house into a GFCI outlet on the
temporary drop. I had to fix one ground/neutral short in new (bad, DIY)
wiring, but apart from that I was able to run the whole house (including
shallow well pump) from that GFCI outlet. Just to be sure I wasn't fooling
myself I used my plug-in GFCI tester on some outlets in the house and it
did indeed trip the GFCI.
All things considered I thought this was a pretty good indication that
minimal leakage requirement are pretty easy to meet. That said, at home
I do get nuisance trips from lightning and there doesn't seem to be much
to do about this. I also used to get trips when the gaskets in cheap(?)
floodlight holders got wet, but I made teflon replacements that don't
have this problem.
re: "use power tools on such as 13 amp table saws and 15 cicrular
You have 15 circular saws? Wow! ;-)
I've been using corded hand tools on GFCI's for a couple of decades
and as far as I recall, none of them have ever tripped the receptacle.
Not sure of current codes, but code used to allow a dedicated (single)
outlet to serve utilization equipment in a GFI mandated distance.
Code also used to require a 20 amp laundry circuit.
Your inspector will have the required information.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.