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01-29-2009, 07:45 PM
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#21
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Wish I was in the water
Join Date: Aug 2007
Location: St. Cloud, Fl
Posts: 461
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I'll post a question even though I didn't answer one. There hasn't been any posted that I could get to in time.
At what percentage for a service, do you calculate a heat pump with a supplemental electric heat. The supplemental heat is not prevented from coming on at the the same time as the heat pump.
A) 100% heat pump/100% supplemental
B) 100% heat pump/65% supplemental
C) The highest of the two, drop the lowest
D) 100% heat pump/50% supplemental
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01-29-2009, 08:11 PM
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#22
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Senior Member
Join Date: Jan 2009
Location: NC
Posts: 601
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Quote:
Originally Posted by BuzzKill
2005 c) 460.8
If the allowable current in a copper bus bar is 1000amps psi of cross section, the width of a standard 1/4inch bus bar designed to carry 1500 amps would be____.
a)2"
b)4"
c)6"
d)8"
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C--- 6" 1/4 * 6= 1.5
1.5 *1000= 1500.
What is the minimum size EGC that I need to wire a 60 amp circuit that has the ungrounded conductors upsized to a #2 copper for VD. Assume a #6 would have been needed before the VD.
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01-29-2009, 08:17 PM
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#23
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Senior Member
Join Date: Jan 2009
Location: NC
Posts: 601
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Quote:
Originally Posted by Greg
I'll post a question even though I didn't answer one. There hasn't been any posted that I could get to in time.
At what percentage for a service, do you calculate a heat pump with a supplemental electric heat. The supplemental heat is not prevented from coming on at the the same time as the heat pump.
A) 100% heat pump/100% supplemental
B) 100% heat pump/65% supplemental
C) The highest of the two, drop the lowest
D) 100% heat pump/50% supplemental
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If we are talking dwelling units then Art. 220.82 (C) (3) . Ans. B
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01-29-2009, 08:28 PM
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#24
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Wish I was in the water
Join Date: Aug 2007
Location: St. Cloud, Fl
Posts: 461
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Quote:
Originally Posted by electricista
What is the minimum size EGC that I need to wire a 60 amp circuit that has the ungrounded conductors upsized to a #2 copper for VD. Assume a #6 would have been needed before the VD.
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250.122 (B)
#6 awg
Therefore #8 increased by 40% = a #6awg
__________________
If you're gonna be stupid, you better be tough.
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01-29-2009, 08:31 PM
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#25
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Wish I was in the water
Join Date: Aug 2007
Location: St. Cloud, Fl
Posts: 461
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Quote:
Originally Posted by electricista
If we are talking dwelling units then Art. 220.82 (C) (3) . Ans. B
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correct
__________________
If you're gonna be stupid, you better be tough.
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01-29-2009, 09:29 PM
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#26
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Motor Repair&Control Shop
Join Date: Jan 2009
Location: Pennsylvania
Posts: 252
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2005 NEC
When can a feeder from service equipment to a remote panelboard be permitted to run in flexible metal conduit?
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01-29-2009, 10:00 PM
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#27
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Senior Member
Join Date: Jan 2009
Location: NC
Posts: 601
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Quote:
Originally Posted by Greg
250.122 (B)
#6 awg
Therefore #8 increased by 40% = a #6awg
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Not sure how you got your answer . Where did the #8 come from? Where did the 40 % come from?
#6 = 26240 cir mil
#2 = 66360 cir mil
66360/26240 means that #2 is 2.53 times larger than a #6 not 40%-- am I doing something wrong?
A #10 is needed for an egc with a 60 amp breaker without upsizing the conductor. So a
#10 = 10380 cir mil
Multiply this by 2.52 and we get 26261 cir mil.
Table 8 says we need a #4
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02-05-2009, 01:29 AM
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#28
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Junior Member
Join Date: Feb 2009
Location: Aus
Posts: 1
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Question
What is the maximum overload protection for a 2hp single phase 115volt motor?
a) 27.6 amps
b)30amps
c)31.2amps
d)35amps
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02-05-2009, 07:03 AM
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#29
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Senior Member
Join Date: Jan 2009
Location: NC
Posts: 601
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Quote:
Originally Posted by Luke.Anderson
What is the maximum overload protection for a 2hp single phase 115volt motor?
a) 27.6 amps
b)30amps
c)31.2amps
d)35amps
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I am terrible with these question but I would have said none of the above based on 430.32(C). Table 430.248 states 2hp means 24 amps. 24*1.4=33.6. Now I have no knowledge of what increments of overloads protection are available-- If I were to guess it would be (B) or (C).
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02-05-2009, 10:15 AM
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#30
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Wish I was in the water
Join Date: Aug 2007
Location: St. Cloud, Fl
Posts: 461
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Quote:
Originally Posted by Luke.Anderson
What is the maximum overload protection for a 2hp single phase 115volt motor?
a) 27.6 amps
b)30amps
c)31.2amps
d)35amps
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Assuming the motor does not have a service factor of 1.15 or a temp rise of 40c the answer would be C 31.2 amps.
__________________
If you're gonna be stupid, you better be tough.
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02-05-2009, 11:12 AM
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#31
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Member
Join Date: Jan 2009
Location: Alabama
Posts: 71
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(C) it is
What is the minimum conductor size that can be used in this capacitor circuit?
The capacitor is rated at 50A, the conductors are to be copper THHN rated at 90*C ran in conduit.
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02-05-2009, 04:49 PM
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#32
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Senior Member
Join Date: Jan 2009
Location: NC
Posts: 601
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Quote:
Originally Posted by Greg
Assuming the motor does not have a service factor of 1.15 or a temp rise of 40c the answer would be C 31.2 amps.
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If you would I would love to understand this as I am weak in this area. Could you or someone else please explain further with code reference.
Never mind I found it.
Last edited by electricista; 02-05-2009 at 06:13 PM.
Reason: To add last sentence
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02-06-2009, 12:18 AM
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#33
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Senior Member
Join Date: Dec 2007
Posts: 123
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Ok heres one: What is the maximum amount of time that christmas lights can be left up for?
A. 180 days
B. 60 days
C. 45 days
D. 90 days
E. 365 days
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02-06-2009, 02:40 AM
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#34
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Member
Join Date: Jan 2009
Location: Alabama
Posts: 71
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Quote:
Originally Posted by pudge565
Ok heres one: What is the maximum amount of time that christmas lights can be left up for?
A. 180 days
B. 60 days
C. 45 days
D. 90 days
E. 365 days
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(D) 590.3 B
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“If it weren't for electricity we'd all be watching television by candlelight.” 
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02-06-2009, 02:43 AM
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#35
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Member
Join Date: Jan 2009
Location: Alabama
Posts: 71
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What is the minimum conductor size that can be used in this capacitor circuit?
The capacitor is rated at 50A, the conductors are to be copper THHN rated at 90*C ran in conduit.
__________________
“If it weren't for electricity we'd all be watching television by candlelight.”
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02-06-2009, 04:19 AM
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#36
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Member
Join Date: Sep 2008
Location: New York
Posts: 95
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Quote:
Originally Posted by electro916
2005 NEC
When can a feeder from service equipment to a remote panelboard be permitted to run in flexible metal conduit?
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Only on fridays. I am sorry I couldnt resist.
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02-07-2009, 09:00 PM
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#37
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Rodentia Rattus
Join Date: Oct 2008
Location: Atlanta, Ga.
Posts: 1,460
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Luke had the right response to Greg's repeat of my original question, it is c: "maximum" is the key word here...430.32(c) is the right code ref (2005 NEC).
New question!!
A 3-phase delta-wye transformer 480/208/120v has a 45kva load; the secondary line current would be aprox.____ and the primary would be aprox.____.
a) 54.1
b) 31.2
c) 73.4
d) 125
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02-08-2009, 08:16 AM
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#38
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Wish I was in the water
Join Date: Aug 2007
Location: St. Cloud, Fl
Posts: 461
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Quote:
Originally Posted by BuzzKill
Luke had the right response to Greg's repeat of my original question, it is c: "maximum" is the key word here...430.32(c) is the right code ref (2005 NEC).
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Not to split hairs but I had the right response. Luke has the plagiarism violation.
__________________
If you're gonna be stupid, you better be tough.
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02-08-2009, 09:25 AM
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#39
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Senior Member
Join Date: Jan 2009
Location: NC
Posts: 601
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Quote:
Originally Posted by BuzzKill
Luke had the right response to Greg's repeat of my original question, it is c: "maximum" is the key word here...430.32(c) is the right code ref (2005 NEC).
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I would have to say this is not correct. The information is not given to assume the motor is nor a 1.15 service factor or 40C or less. Given the question what is the max. overload with no other info I would still respond 140% not 130%. If thequestion had stated the motor had a service factor of less than 1.15 and a marked temp rise of greater than 40C than I would agree.
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02-08-2009, 10:56 AM
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#40
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Wish I was in the water
Join Date: Aug 2007
Location: St. Cloud, Fl
Posts: 461
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I agree but on a Prometric test if they do not give you that data you would go with the 130% answer. Test facilities will generally give you that additional info if they are looking for the 140% answer.
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