# Building Controls Guys blowing our $25 fuses



## Southeast Power (Jan 18, 2009)

Back to the NEMA 4x Job.
The building controls guys decided to connect the line and load side of one of the control transformers to the 480 volts and totally grenaded it. 









Off to Grainer to buy a $150 replacement and a couple more of those fancy low peak fuses.

I get a call yesterday, about 3PM, they blew a couple more fuses.
I politely let them know where Grainger was and to have a nice day.

I was just way too nice with these guys and wanted to help the project along but, Im sure I have over $1000 in transformers and fuses invested that I will never see again.


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## flyboy (Jun 13, 2011)

Why will you never see the "over $1,000 in transformers and fuses" again? Pray tell...


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## Bird dog (Oct 27, 2015)

flyboy said:


> Why will you never see the "over $1,000 in transformers and fuses" again? Pray tell...


They should. If I did something stupid, my boss would pay for it & I may get a pink slip. :surprise:


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## Signal1 (Feb 10, 2016)

Line AND load side to 480?

How'd they manage that?


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## 99cents (Aug 20, 2012)

That big a mess with Low Peaks? Wow.


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## Southeast Power (Jan 18, 2009)

flyboy said:


> Why will you never see the "over $1,000 in transformers and fuses" again? Pray tell...


Ill get something out of it but, Its a government project, they have to have a change order approved to pay us, the building mechanical was completely shut down, not a soul in the world could get what they needed.

This is a good argument why not to work for crappy GCs or why not to do plan and spec work.


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## JRaef (Mar 23, 2009)

I had an HVAC guy once blow up a 250HP VFD. When I went to go look at it, the input and output conductors were backward. I asked him about it, his response was this:


"Well, I looked at the drive terminals and they said "Line" and "Load". Then I looked at the breaker in the distribution panel, the terminals said "Load" and I looked at the connection diagram on the motor and it said "Line". So I connected Line to Line and Load to Load! What's the problem?"


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## Bird dog (Oct 27, 2015)

JRaef said:


> I had an HVAC guy once blow up a 250HP VFD. When I went to go look at it, the input and output conductors were backward. I asked him about it, his response was this:
> 
> 
> "Well, I looked at the drive terminals and they said "Line" and "Load". Then I looked at the breaker in the distribution panel, the terminals said "Load" and I looked at the connection diagram on the motor and it said "Line". So I connected Line to Line and Load to Load! What's the problem?"


and that's why boys & girls OCPDs protect OUR wire. :vs_mad:


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## PVGuy (Apr 22, 2017)

JRaef said:


> I had an HVAC guy once blow up a 250HP VFD. When I went to go look at it, the input and output conductors were backward. I asked him about it, his response was this:
> 
> "Well, I looked at the drive terminals and they said "Line" and "Load". Then I looked at the breaker in the distribution panel, the terminals said "Load" and I looked at the connection diagram on the motor and it said "Line". So I connected Line to Line and Load to Load! What's the problem?"


OMG. Were you tempted to connect the HVAC guy to those breaker load terminals?

Back when people still had tape decks in their stereo systems, manufacturers eventually had to start labeling the associated jacks "record" and "play" because folks would connect the tape deck "input" jacks to the receiver/amp tape "input" jacks, and, yep, outputs to outputs.


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## Kevin (Feb 14, 2017)

PVGuy said:


> OMG. Were you tempted to connect the HVAC guy to those breaker load terminals?
> 
> Back when people still had tape decks in their stereo systems, manufacturers eventually had to start labeling the associated jacks "record" and "play" because folks would connect the tape deck "input" jacks to the receiver/amp tape "input" jacks, and, yep, outputs to outputs.


That explains why I've seen tape players marked with both input/record and output/play


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## Quickservice (Apr 23, 2020)

JRaef said:


> I had an HVAC guy once blow up a 250HP VFD. When I went to go look at it, the input and output conductors were backward. I asked him about it, his response was this:
> 
> 
> "Well, I looked at the drive terminals and they said "Line" and "Load". Then I looked at the breaker in the distribution panel, the terminals said "Load" and I looked at the connection diagram on the motor and it said "Line". So I connected Line to Line and Load to Load! What's the problem?"


:vs_laugh::vs_laugh:I love the “What’s the problem?” part! Last winter I had a home owner ask me that question after his heat pump died and he proceeded to fill his house with 1500W portable heaters. :vs_OMG:


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## Norcal (Mar 22, 2007)

Southeast Power said:


> Back to the NEMA 4x Job.
> The building controls guys decided to connect the line and load side of one of the control transformers to the 480 volts and totally grenaded it.
> 
> 
> ...



Reminds me of the tales of Doofy on another forum, one of Doofy's antics was to connect all line taps of multi tapped HID ballasts in wall packs to 277V. Yes, he did it to a number of them.


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## paulengr (Oct 8, 2017)

Jeez...this goes back about 20 years ago but contractors around here wired up a 2400:480 V transformer with the primary and secondary sides switched. One of the plant electricians went to test the output voltage on the "480 V" side with his non-UL 61010 meter (CAT rating, before that was a thing) and got his first trip to the burn unit.


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