Running Power for portable dimmers

[ethelirene]

I'd like to add a few more dimmers backstage for sidelight, as most of our circuits are front of house. Looking at a portable dimmer pack, Sensor 3 12 module portable,SP3-2420 (http://www.etcconnect.com/docs/docs...3L1002_Sensor3_Portable_Packs_Spec_Sht_vD.pdf) Our space has a 400A company switch backstage, with a Cam Lock breakout. I originally assumed I could simply run power from that to the pack, but our physical plant is saying that I need to have a separate 160Acircuit installed (based on the information in the spec in red blow) as if I run the pack from the company switch it will be over fused? I feel like I'm missing something?

1. The dimmer pack may operate on either 3-phase, 4-wire + ground, 120/208V, 50/60Hz AC or 1-phase, 3-wire + ground, 120/240V, 50 or 60Hz, AC at an amperage sufficient to power the pack.

1) SP12 – 12-Module Pack (Model - Dimmers – Power)

a) SP3-2415 24x15A 120A 3Æ /180A 1Æ

b) SP3-2420 24x20A 160A 3Æ /240A 1Æ

c) SP3-1250 12x50A 200A 3Æ /300A 1Æ

d) SP3-6100 6x100A 200A 3Æ /300A 1Æ

 

[BillConnerFASTC]

Does the Co Sw have fuses - and just change to 150's? (You won't need 160 - you'll never fill every dimmer to 2400 watts at full on - wouldn't be surprised if a 100 wouldn't be fine.) Otherwise I would think a portable distro box that connects to the company switch would be the most economical and flexible choice - unless you plan to use the new 24 pack in that same place and only there.

 

[jhochb]

Good Morning


1. . The dimmer pack may operate on either 3-phase, 4-wire + ground, 120/208V, 50/60Hz AC or 1-phase, 3-wire + ground, 120/240V, 50 or 60Hz, AC
at an amperage sufficient to power the pack.

The NEC is setup to prevent fire & personal injury
You have a dimmer that requires a 160A service. You need over-current protection closer to the 160A rating to be safe.
If there were a short or over-current say 200A the 400A fuses wouldn’t care but your feeder cables would.


Bill is right about a portable distro but a 400A fuse is typically physically larger than a 150
You may not find one that fits.

 

[DrPinto]

Not meaning to get off topic here, but can someone tell me why there are places for padlocks on the green, red, and blue outlets? Wouldn't it make more sense to have the locks on the black, red, and blue outlets?

 

[SteveB]

Not meaning to get off topic here, but can someone tell me why there are places for padlocks on the green, red, and blue outlets? Wouldn't it make more sense to have the locks on the black, red, and blue outlets?

Sounds like the guy that installed the padlocks is color blind and couldn't differentiate green from black.

 

[SteveB]

If a circuit breaker company switch, check if the breaker can be dialed down to a lower amperage protection setting.

If memory serves,remember that once you de-rate the company switch to close to the pack feeder cable capacity, the pack must be within 5ft of the protection,. else you will need a separate distro.

 

[ethelirene]

Good Morning


1. . The dimmer pack may operate on either 3-phase, 4-wire + ground, 120/208V, 50/60Hz AC or 1-phase, 3-wire + ground, 120/240V, 50 or 60Hz, AC
at an amperage sufficient to power the pack.

The NEC is setup to prevent fire & personal injury
You have a dimmer that requires a 160A service. You need over-current protection closer to the 160A rating to be safe.
If there were a short or over-current say 200A the 400A fuses wouldn’t care but your feeder cables would.


Bill is right about a portable distro but a 400A fuse is typically physically larger than a 150
You may not find one that fits.

Hi Jack
So if I inturepret your post correctly, it might just be easier in the long run to have that second circuit run? They're unwilling to re-fuse the Co sw regardless, and the distro would still be over fused?

 

[JD]

This is an ETC rack right? Check with ETC, but from what I remember, if the rack is equipped with E1016 cams, then it is bussed for a 400 amp capacity, you just have less dimmers. Your feeder would have to be gauged at the full 400 amps, even though your draw would be much lower. If you wanted to reduce your feeder size, then you would have to limit your OCPD down to the desired feeder.

The only limiter rating I see in the paperwork is that of the optional pass-through cam panel.

Not meaning to get off topic here, but can someone tell me why there are places for padlocks on the green, red, and blue outlets? Wouldn't it make more sense to have the locks on the black, red, and blue outlets?

Pretty Strange!

 

[FTKD]

Agreed--Your Physical Plant guy should be on board once you explain (and show him in the ETC paperwork) that everything is bused for 400A. For that you will need 4/0 feeder cable which will be pricey but if you don't need to go far it shouldn't be too bad. Your other option would be if this is only a couple times a year deal to just rent a dimmer rack and appropriate feeder from your local production vendor.

 

[techieman33]

Not meaning to get off topic here, but can someone tell me why there are places for padlocks on the green, red, and blue outlets? Wouldn't it make more sense to have the locks on the black, red, and blue outlets?

I could see having locks on the red and blue for situations where you hook up something only using one phase. Since the switch should be locked you should only need to lock them when the power is hot. I don't see any need to lock the ground though.

 

[DrPinto]

I think I just answered my own question about the locks. Looks like the panel has some sort of safety interlock that requires you to connect the cables in a certain order or the next outlet cover will not open. Kind of cool, actually...

View attachment Posi-Lok.pdf

 

[JD]

I think I just answered my own question about the locks. Looks like the panel has some sort of safety interlock that requires you to connect the cables in a certain order or the next outlet cover will not open. Kind of cool, actually...

View attachment 9364

Looks like you have to use their special male shells with the connectors. Does look interesting though!

More info- http://store.jbn-duraline.com/library/Documents/e0400_series_catalog.pdf

 

[BillConnerFASTC]

The supply must be sized for the connected load. The dimmer rack capacity is not load.

 

[ethelirene]

The supply must be sized for the connected load. The dimmer rack capacity is not load.

Would you mind fleshing that out a little more? I feel like I might be getting arguements from both sides
1) the 400 is fine, just have appropriately rated cables and operate the rack with fewer dimmers
Or
2) go with the arguements of installing a lower amperage circuit, as its more appropriate for the load?
Am I interpreting this correctly?

 

[BillConnerFASTC]

Would you mind fleshing that out a little more? I feel like I might be getting arguements from both sides
1) the 400 is fine, just have appropriately rated cables and operate the rack with fewer dimmers
Or
2) go with the arguements of installing a lower amperage circuit, as its more appropriate for the load?
Am I interpreting this correctly?

Sorry. I meant to reply with quote:

"1. . The dimmer pack may operate on either 3-phase, 4-wire + ground, 120/208V, 50/60Hz AC or 1-phase, 3-wire + ground, 120/240V, 50 or 60Hz, AC
at an amperage sufficient to power the pack.

The NEC is setup to prevent fire & personal injury
You have a dimmer that requires a 160A service. You need over-current protection closer to the 160A rating to be safe.
If there were a short or over-current say 200A the 400A fuses wouldn’t care but your feeder cables would."

I can't make best recommendation without an idea if: this is a one time or infrequent set up or if you will use this regularly, say at least two events per year; and what kind of load do you anticipate - two 575s per dimmer or less or more?

I think the suggestion that the rack is rated for 400 amp feed should be verified but a set of feeders for that is the easiest and least expensive and per code. But if using often and especially if a new feeds in someone else's budget thana dedicated receptacle or hard wiring the rack is not a bad choice - tapping off the co sw feed or other. I would be concerned about distribute back to rack and noise. No doubt installing in a separate room and installing a permanent distro would be best but most expensive. In which case 100 or 125 amp 3 pole is probably fine but tell us how you think you'll loa it.

 

[derekleffew]

The supply must be sized for the connected load. The dimmer rack capacity is not load.

Hear, here.

Would you mind fleshing that out a little more? ...

See the first PDF at Dimmer feeds--How much power is enough? - ControlBooth .

In my opinion, it's likely not cost-effective to buy and run 4/0 wires to power a 24x2.4kW dimmer pack. Depending on the distance from the company switch to the pack, it might be more fiscally responsible to rent/purchase a 200A disconnect and run 2/0 wire. Or, again depending on distance and connected load, a 100A disconnect and #2 wire.

We've discussed previously our distaste for Posi-Lock panels elsewhere.

 

[STEVETERRY]

Hear, here.

See the first PDF at Dimmer feeds--How much power is enough? - ControlBooth .

In my opinion, it's likely not cost-effective to buy and run 4/0 wires to power a 24x2.4kW dimmer pack. Depending on the distance from the company switch to the pack, it might be more fiscally responsible to rent/purchase a 200A disconnect and run 2/0 wire. Or, again depending on distance and connected load, a 100A disconnect and #2 wire.

We've discussed previously our distaste for Posi-Lock panels elsewhere.

And here are NEC sections 520.53(h)(3) and (4) that allow smaller cables on the 400A switch:

(3) Supply Conductors Not Over 3.0 m (10 ft) Long. Where supply conductors do not exceed 3.0 m (10 ft) in length between supply and switchboard or supply and a subsequent overcurrent device, the supply conductors shall be permitted to be reduced in size where all of the following conditions are met:

(1) The ampacity of the supply conductors shall be at least one-quarter of the current rating of the supply overcurrent protective device.

(2) The supply conductors shall terminate in a single overcurrent protective device that will limit the load to the ampacity of the supply conductors. This single overcurrent device shall be permitted to supply additional overcurrent devices on its load side.

(3) The supply conductors shall not penetrate walls, floors, or ceilings or be run through doors or traffic areas. The supply conductors shall be adequately protected from physical damage.

(4) The supply conductors shall be suitably terminated in an approved manner.

(5) Conductors shall be continuous without splices or connectors.

(6) Conductors shall not be bundled.

(7) Conductors shall be supported above the floor in an approved manner.

(4) Supply Conductors Not Over 6.0 m (20 ft) Long. Where supply conductors do not exceed 6.0 m (20 ft) in length between supply and switchboard or supply and a subsequent overcurrent protection device, the supply conductors shall be permitted to be reduced in size where all of the following conditions are met:

(1) The ampacity of the supply conductors shall be at least one-half of the current rating of the supply overcurrent protective device.

(2) The supply conductors shall terminate in a single overcurrent protective device that limits the load to the ampacity of the supply conductors. This single overcurrent device shall be permitted to supply additional overcurrent devices on its load side.

(3) The supply conductors shall not penetrate walls, floors, or ceilings or be run through doors or traffic areas. The supply conductors shall be adequately protected from physical damage.

(4) The supply conductors shall be suitably terminated in an approved manner.

(5) The supply conductors shall be supported in an approved manner at least 2.1 m (7 ft) above the floor except at terminations.

(6) The supply conductors shall not be bundled.

(7) Tap conductors shall be in unbroken lengths.

ST

 

[JD]

So basically:

1) The rack is fine on a 400 amp switch

2) If your feed is going to be long, it may be cheaper to use a distro to introduce a 100 or 200 amp OCPD before the feed.

3) If your feed is shorter than 10 feet (Switch to rack) than smaller feeds are allowed provided the conditions listed above are met.

 

[BillConnerFASTC]

So basically:

1) The rack is fine on a 400 amp switch

2) If your feed is going to be long, it may be cheaper to use a distro to introduce a 100 or 200 amp OCPD before the feed.

3) If your feed is shorter than 10 feet (Switch to rack) than smaller feeds are allowed provided the conditions listed above are met.

Good summary. I would again suggest if this is to be more or less permanent and used a lot, a new feed and locating it in another room may be worthwhile. The next thread on the same project is often how do I quiet the fan noise of the dimmer rack I just set back stage? You may get away with it for a dance concert with loud recorded music, not so much if used for the next two character play.

 

[STEVETERRY]

So basically:

1) The rack is fine on a 400 amp switch

2) If your feed is going to be long, it may be cheaper to use a distro to introduce a 100 or 200 amp OCPD before the feed.

3) If your feed is shorter than 10 feet (Switch to rack) than smaller feeds are allowed provided the conditions listed above are met.

......or shorter than 20 feet, allowing cable half the ampacity of the OCPD, instead of the quarter ampacity allowed at 10 feet or less.

ST