4X flashpoint 320M for the first time, how many can I hook to same extension cord?

Foxtrot_01

TPF Noob!
Joined
Jan 7, 2009
Messages
123
Reaction score
1
Location
Miami, FL
Hello all,
I hope everyone is well. I finally opened my 4 flashpoint 320m's, I am looking to use the four 320m's in a shoot this week, one as the main, one as the fill and two directed to the backdrop.

I have used off camera flashes so this is my first time, I don't want to burn my condo to the ground so my question is, how many of these flashpoint 320m's can I hook to the same extension cord/outlet?

I have wall a/c all over the condo, so if there is a hair dryer feeding from the same breaker as one of the AC's the breaker will go off.

my plan is to pick a breaker that doesn't have an AC connected to it.

So the main question is, if I have four of these guys firing at the same time, can I hook them up to the same outlet(extension cord) or do I split them in two outlets or one per outlet?

sorry if this is a dumb question, I have no experience using monolights, I would assume since these also can feed from a battery the drain cant be that great.

thank you for you assistance.
 

tirediron

Watch the Birdy!
Staff member
Supporting Member
Joined
Jul 8, 2005
Messages
45,747
Reaction score
14,804
Location
Victoria, BC
Website
www.johnsphotography.ca
Can others edit my Photos
Photos OK to edit
I can't speak to the 320 in particular, but most monolights only draw a couple of amps when charging, and each duplex outlet is 15 amps; two will be fine, three shouldn't be an issue, and if there's no load, then you probably could do four. Worst case is you'll trip a breaker.
 

Derrel

Mr. Rain Cloud
Joined
Jul 23, 2009
Messages
48,227
Reaction score
18,929
Location
USA
Website
www.pbase.com
Can others edit my Photos
Photos OK to edit
Make sure to use a good quality extension cord, not some flimsy little "brown cord".
 

Gavjenks

TPF Noob!
Joined
May 9, 2013
Messages
2,976
Reaction score
588
Location
Iowa City, IA
Can others edit my Photos
Photos OK to edit
Flashpoint 320M = 150 watts each = 1.25 amps
Since you're in a condo where other random things might be attached to a circuit, let's assume 5 amps are being used by other stuff.
Most wall outlets in the US are 20 amps (you can check your breaker box though, some are 15. Usually 15 is only for lighting fixtures).

So you can probably use about 12 amps at least for lighting, even if you have a computer and a TV and a desk lamp running in the same room or something, which means you could plug 9-10 monolights into a single circuit without really risking tripping the breaker (bad in the middle of a shoot...).

With an extension cord from another circuit in a different room, you could bring another 9-10 into your studio, lol.
 

tirediron

Watch the Birdy!
Staff member
Supporting Member
Joined
Jul 8, 2005
Messages
45,747
Reaction score
14,804
Location
Victoria, BC
Website
www.johnsphotography.ca
Can others edit my Photos
Photos OK to edit
Flashpoint 320M = 150 watts each = 1.25 amps

Ummm.... the Flashpoint is 150 Watt-seconds which is a measurement of light output. The current draw to charge the capacitors will likely be higher, and checking the specs page, it uses a 10 amp fuse, so it's probably more of the 5-7 amps at peak.
 

Gavjenks

TPF Noob!
Joined
May 9, 2013
Messages
2,976
Reaction score
588
Location
Iowa City, IA
Can others edit my Photos
Photos OK to edit
Flashpoint 320M = 150 watts each = 1.25 amps

Ummm.... the Flashpoint is 150 Watt-seconds which is a measurement of light output. The current draw to charge the capacitors will likely be higher, and checking the specs page, it uses a 10 amp fuse, so it's probably more of the 5-7 amps at peak.

It's pretty much the same as watts in my experience for power draw (not my experience in monolights. I've never used more than 2. But rather electricity in general). Most units take about 1 second to recycle (or longer), and almost that entire time, they will be at a wattage similar to their watt-seconds, OR much lower (if they cycle more slowly for cheap units like this). There may be a very brief spike in draw right after the flash, but it is typically only double the advertised watt-second rating (e.g. these might draw 2.5A peak), and it doesn't necessarily trip breakers like you would expect it to even then.

The reason is because it is too short of a time that the overcurrent exists to actually trip the breaker. Most normal breakers don't trip instantly. There is a time curve for how quickly they trip based on how much overcurrent. If you run 23 amps through a 20 amp breaker, it may well not trip for an hour, or ever. If you run 40 amps through it, it might trip in, say, 30 seconds. 100 amps, maybe 1 second or something. If 10 monolights only draw 50-70 combined amps for a millisecond of time and then sharply fall off exponentially, they probably won't ever trip a 20 amp breaker.

Will it damage your wires? Almost certainly not. Plus, I wasn't really seriously expecting him to use 10 monolights, (but I low-balled that number quite a bit anyway. Even at 2.5 amps double peak current draw, that only add up to 25 amps, which would likely take minutes to trip a breaker, if ever, even sustained at that level, much less a few milliseconds).

There's a reason why breakers with fairly shallow time curves are acceptable for fire codes: If the overdraw is small enough to not trip the breaker, then it's been rated purposefully to be low enough to not pose much danger in melting your wires. The higher the current, the faster wires heat up, so the amount over the maximum matters a lot, and the breakers scale their breaking speed accordingly. Breakers work very differently than, say, GFCI outlets which are made to shut off as fast as possible to not electrocute people. The goal is merely fire protection.

If you're paranoid about it anyway and actually want to use a dozen monolights for some silly reason, the cheapest solution is just having extension cords and dividing your ridiculous number of monolights across 2-3 circuits in the building. Next cheapest is buying a battery pack and inverter to cushion your house's electrical system from the peak draw.
 
Last edited:

nycphotography

No longer a newbie, moving up!
Joined
Dec 7, 2012
Messages
963
Reaction score
261
Can others edit my Photos
Photos NOT OK to edit
Make sure to use a good quality extension cord, not some flimsy little "brown cord".

For strobes, even the flimsy brown cords are fine. You'll pull maybe 10 amps for a half second... not nearly enough to heat the cord, even when shooting pretty fast.

Now with 4 x 1000w HOT LIGHTS, you better bring in the electrician ;-)

A 1200 watt hair dryer pulls 10 amps for 15 minutes solid.... And they also work fine w/ a skinny cord.

By comparison, my air compressor (or any heavily loaded electric motor) will pull a large current spike for a very short time in order to get started, after which it pulls maybe 12 amps. The pulse is too short to pop a breaker, but if the cord won't deliver the current spike, the compressor simply won't start. Even an orange drop cord won't work past 25' or so. I have a special solid copper (romex) cord I made for it. Even then, it's more about the ability to deliver the very short term 'starting current', and not so much about the total load on the drop cord.

short answer: 3-4 strobes = go for it, no worries.
 

Most reactions

ClickASnap

New Topics

Top