how can 4K HMI use 120volts?

[Dennis Hingsberg]

Hi,

 

Was looking at getting an old 4K HMI off a local company. It's a Stand Sirio 4K HMI frensel with Quartzcolor magnetic ballast. Model 2080 if I remember correctly.

 

Apparently it's 120 volts, but how can it be a 4Kw in power if max per circuit is 15 amps, or around 2000 watts?

 

Lastly, anything to look out for when buying such aged equipment? Moreso the ballast I'd be worried about.

 

Cheers, thanks,

 

[Jay Young]

Max household circuit is usually between 15-20 amps. From a lunchbox you might could get 40 amps.

[Mark Kenfield]

Hey Dennis,

 

I'm sure one of our far more knowledgable gaffers on here will chime in shortly and explain this much more clearly than I can. But basically (as I understand it) you'd need a bit under 40 amps to power a 4kw HMI on 120v, which means you'd need a distro box that could step-down from three-phase power to give you the necessary amperage on a single-phase socket.

 

Then you just plug and play.

 

Cheers,

 

Mark

Edited July 25, 2016 by Mark Kenfield

[David Mullen ASC]

Hi,

 

Was looking at getting an old 4K HMI off a local company. It's a Stand Sirio 4K HMI frensel with Quartzcolor magnetic ballast. Model 2080 if I remember correctly.

 

Apparently it's 120 volts, but how can it be a 4Kw in power if max per circuit is 15 amps, or around 2000 watts?

 

 

 

You can't run a 4K off of a household circuit, for that very reason. Are you saying they stuck an ordinary household plug on the end of it?

[Stuart Brereton]

You can't run a 4k from 120v house power. The ballast most likely has a 60a Bates connector on it, so that you can plug in to a distro box being fed from a generator.

[Adrian Sierkowski]

Exactly. When you get into things over a 2K then you start to get into things which will require you to in some way run your own distribution system.
Normally you'd run cable from your powerplant (genny) to nearby your set, and then into a large distro box. This will break you out into 100A bates connectors (which you can connect to an array of 100A lights)-- either 120 or 240-- From one of your 100A legs you're then split into, sometimes, 2 60A bates connectors, or just go directly into a 100A lunchbox etc. Hence how you can run a 40Aish light.
In the end it's much better to bring power yourself since you can really put any light anywhere, -v- ferreting around for outlets etc.

[Dennis Hingsberg]

Thanks for replies. I don't know why I assumed it would plug into 120v 15 amp circuit. Knew something was missing from my assumption, glad I asked.

 

In the meantime seller advised it has 60 amp stage pin.

[John E Clark]

You would have to get a generator, or have the incoming line to the location 'wired' for providing 33 amps (4000/120 = 33) Now, things I deal with aren't that high typically, but in most electronic circuits that have some sort of 'ballast', or 'voltage conditioning' there is additional draw on the line, especially during startup, and so my basic 'rule of thumb' has been to have lines that are 2x the nominal power, for that startup period.

 

That would suggest an 66 amp line...

 

Even if one had 240 V that would still be 30 or so amps.

Edited July 27, 2016 by John E Clark

[JD Hartman]

You would have to get a generator, or have the incoming line to the location 'wired' for providing 33 amps (4000/120 = 33) Now, things I deal with aren't that high typically, but in most electronic circuits that have some sort of 'ballast', or 'voltage conditioning' there is additional draw on the line, especially during startup, and so my basic 'rule of thumb' has been to have lines that are 2x the nominal power, for that startup period.

 

That would suggest an 66 amp line...

 

Even if one had 240 V that would still be 30 or so amps.

 

What are you saying here? Have the electrical service or "drop" rewired? Are you suggesting that an additional circuit be added to the location? I've don't think I've ever seen a 33 or 66A breaker, not even as a molded case IEC type.. In the US, standard single pole breaker amperage's are: 15; 20; 30; 40; 50; 60; etc.

 

Curious......"other" does that mean licensed Electrician or unlicensed Electrician's helper, apprentice, journeyman or film industry "spark"?

[John E Clark]

 

What are you saying here? Have the electrical service or "drop" rewired? Are you suggesting that an additional circuit be added to the location? I've don't think I've ever seen a 33 or 66A breaker, not even as a molded case IEC type.. In the US, standard single pole breaker amperage's are: 15; 20; 30; 40; 50; 60; etc.

 

Curious......"other" does that mean licensed Electrician or unlicensed Electrician's helper, apprentice, journeyman or film industry "spark"?

 

I was calculating the draw of the lamp its self. Once on knows that one can then determine what circuit would handle such. For residential power and 4K, other than the 240V circuit for the dryer or other 'kitchen' appliances, there is typically no 'easily' already installed circuit and attendant plug available.

 

When dealing with any form of electricity I would only hire the services of a licensed electrician to make changes to the distribution box, put in new lines, etc.

 

So, when I estimate a draw of 66 Amps on startup, and 33 amps continuous, so that would suggest a line that is above 60 amps...

 

Do people get away with using things in places that may be 'underpowered' or not properly wired, sure... but in terms of safety, it's about the only place I'm 'conservative'.

 

Modern ballasts may be better on the peak draw. But older ones may not be so good. Older house wiring may not be up to either, even for the 240V lines.