"REL" wrote in message
...
On Mon, 24 Nov 2003 20:31:21 GMT, "volts500"
wrote:

Have you brainiacs over there in alt.hvac ever figured out the difference
between MCA and MOCP yet?


Uhm, that would be a past discussion you and I had sir.

At the very least the interpretation is extremely cloudy on that and
you know it as well.


No, REL, it's common knowledge in the electrical industry.......and very
clear. One would think that someone who claims to be trained by the Union
as a Journeyman Wireman would know that. I even provided you with several
avenues to verify what I was saying......such as check out
_any_ HVAC Schedule which easily obtained for the asking at any commercial
construction site which one may be working at and compare those specs to
what's stamped on the nameplates.


You were correct in allowed derating of
conductors, however you also agreed there were other sections within
440.XX that indicated it might not be allowed. We also both took
notice that even if the derating were to be allowed, often times
voltage drop due to length, the larger conductor would be selected
anyway.

But still not as large as the MOCP. The wires aren't derated, they are
sized for the MCA.

All things considered, you were opting to save money on the electrical
installation and I was spending more money to be on the safer side of
the dispute.


Who's money? That argument might be OK for a single dinky residential unit,
but it just doesn't hold water when many large units are considered.


The NFPA 70 or NEC clearly spells out that the code is
NOT the most practical, or even the best, but more specifically it is
the MINIMUM requirements.

No, REL, like I said it's common knowledge in the trade. Even the strictest
Design Engineers will not require the wire size to be sized as large as the
MOCP. Once the volt drop is accounted for, some Hospital and School, etc.
Design Engineers
will bump up the wire and conduit sizes by usually no more than one size,
and then
only to allow for future growth of the facilities. Again, even those
professionals don't require a wire size to meet the full MOCP.


I have no idea why you chose to bring this old settled discussion into
this thread, but now that you have, why not.


Because it fits. The discussion evidently was settled in your
mind.....Grand Puba style. When
two professionals disagree, is not the next logical step step (_IF_ one
really wants to "settle" something) to seek the advice of other
(indifferent) professionals? I believe that a few other professionals in
the group did agree with me, but their comments were seeming ignored, or
buried in the
numerous Piranha attacks. IIRC, I did
offer to take the discussion to alt.engineering.electrical. Declining to do
so, to me anyway, either shows that you don't want the alt.hvac piranhas
(who can contribute nothing but insults) to see that you are wrong, or is
it that you don't perceive the people in AEE expert enough to settle the
matter? Perhaps some known leaders in the electrical industry at this
website will suffice?:
http://electrical-contractor.net/cgi...i?action=intro
If you don't agree with that, then perhaps you can suggest a 3rd party?


Perhaps some one derated
the conductors trying to save a few bucks and the voltage applied to
the motor is too low and has now burned up.

Perhaps. However, that's a volt drop problem......which has nothing with
the crux of that discussion, which was MCA (Minimum Circuit Ampacity) and
MOCP (Maximum OverCurrent Protection). For sake of discussion, increasing
the
wire size to account for volt drop is (or should be) a given.

The three things you mentioned are reasons a motor might not start and
would just hum, there certainly are several more. Low voltage due to
wiring, contacts in relay, or contacts in the breaker. Loose
connections, the list goes on and on.

OK, then, how hard was that?
Although the relay contacts have already been mentioned, and
the other symptoms are closely related, they count. Let's see, we're down
to 93 out of 100 possibilities. I'll even give credit for a few more that I
may have missed in the count.......so let's make it 90 out of 100. Only 90
to go.


Could the repair cost 700 bucks? Well, if the motor is toast because
of bad contacts on the relay, which is commonly on the pc board, I
suppose it could approach that pretty quick. Motor, cap, board,
possibly a new blower wheel if the hub is bad. Yeah, depending upon
the manufacture and the parts cost, it sure could. It also could be a
15 dollar cap and an hours labor plus the service call. I have no
idea, I can not see it from here.


There ya go! That's all that had to be said to the OP from the get go.


At the end of our last conversation you seemed like a pretty decent
guy. You sure were not on a rant like you are this time. In fact, I
have not even watched this thread well enough to know WTF is going on,
just saw your name and thought , well I thought it was sharing info
and not this fussing stuff.


Info _was_ being shared until the alt.hvac Piranhas went into attack mode.


For what it is worth, If I recall
correctly, 90 degree C wire is spec for heaters.

All _anybody_ needs to do is have a look see at the wire between the
terminal block and the heating element of their own equipment to see that
the wire is indeed hi-temp (105C or higher). The feeder _supply_ wires may
only be required to be (usually) 75C, even then, depending on what's called
for by the manufacturer........but since 90C wire is very popular, that's
what usually gets used. CBHVAC claiming that he was going to re-wire and
restring a 200kW duct heater was just ridiculous.....for starters, I'd like
to know what house has a 200kW heater.


The other rich