[SML] Relays vs. Traditional Circuit Breakers for LED Power.

[Dale Farmer]

I'd go back to the vendor and ask them why they suggest this, with 
citations to the manufacturer's technical justification to sell this 
increased cost to the money people.  My suspicion is that it's a high 
profit item.

Sequenced circuit breaker panels are used generally to ramp up heavy 
power demand items in industrial settings.  The power company and it's 
power generating and distribution system don't like sudden large loads 
unexpectedly sucking down lots of electrons.  Say you have a large 
electrically heated tunnel oven in your bakery.  It will have dozens and 
dozens of seperate heating elements.  Turning them on and off in 
sequence gives the power system enough time to respond to the ramp up or 
down of your load.

   the other reason for sequenced breakers is for systems where some 
parts of the gear need to be up and running before other parts.  Like a 
large sound reinforcement system.  You power up the portions of the 
system in order, and the amplifiers get turned on last and turned off 
first.  The transient power up or down noises that are emitted by some 
sound system components can damage speakers if amplified.

Dale


On 8/10/2016 11:29 PM, Rob Graham via Stagecraft wrote:
> They're suggesting "sequenced circuit breaker panels," and/or
> "relay-type dimmers."
>
> On Wed, Aug 10, 2016 at 10:28 PM, Kristi R-C via Stagecraft
> <stagecraft at theatrical.net> wrote:
>> I suspect your suppliers are suggesting "breaker" as opposed to "dimmers"
>> for the LED fixtures and the confusion is in the terminology being used not
>> the location or type of the breakers themselves.
>>
>> Kristi R-C
>>
>>
>>
>> ---- Original Message ----
>> From: tech dept via Stagecraft <stagecraft at theatrical.net>
>> To: Stagecraft Mailing List <stagecraft at theatrical.net>
>> Cc: tech dept <tech.dept at inbox.com>
>> Sent: Wed, Aug 10, 2016 10:03 pm
>> Subject: Re: [SML] Relays vs. Traditional Circuit Breakers for LED Power.
>>
>> It sounds to me like someone is trying to sell you a very exotic bill of
>> goods that you really don't need and could do much cheaper and probably have
>> better reliability a more conventional way. (Standard regular circuit
>> breakers and a relay pack (though I really see no need for the extra step of
>> a relay pack.) I assume all the fixtures are standard theatrical brands and
>> DMX controlled. A nice large 'company switch' (AKA Bulldog) preceding the
>> permanent breaker panel Is all the good night switching I would want for the
>> breakers.
>> An inspector would really raise an eyebrow if you were regularly switching
>> on and off the breaker for non-fault reasons.
>>
>>> -----Original Message-----
>>> From: stagecraft at theatrical.net
>>> Sent: Wed, 10 Aug 2016 21:45:03 -0500
>>> To: stagecraft at theatrical.net
>>> Subject: [SML] Relays vs. Traditional Circuit Breakers for LED Power.
>>>
>>> We're in the midst of looking at upgrading a significant portion of
>>> our stage lighitng to LED in the near future. As part of the
>>> exploration, vendors have suggested the addition/installation of relay
>>> controlled breakers to supply power to the various positions. One of
>>> our own University electricians asked me "why do you have to have
>>> relays, couldn't you just flip the breakers?" I didn't have an answer
>>> that I felt good about giving him, so I'm here now asking the
>>> collective -
>>>
>>> Is there an absolute "must have" reason for the remote relays,
>>> especially given that we're looking at full rack replacement, and the
>>> installation of a new control network anyway? Access to the panel
>>> would be very convenient; it's not likely to be placed in a
>>> hard-to-reach spot. I'd really like to have a reason other than "the
>>> recommendation of the vendor is to use this."
>>>
>>> Thanks in advance for your collective wisdom.
>>>
>>> -RG
>>>
>>> --
>>> Rob Graham
>>> photonguide at gmail.com
>>>
>>>