Surge Current

[MLStrand56]

I don't see any forum for this problem, but it involves my Solid State pwr. amps, so I'll try it here 1st.

I have 5 x Yamaha MX-1000 power Amps. If they are all turned on at once, the Surge Current in the amps, trips the 20 Amp. ckt. breaker in the main Breaker Panel. If I turn them on individually, they will run fine (even Very Loudly) on the same 20 amp. ckt. breaker.

So what I need is a Line Conditioner(?) that will allow me to program a different AC Turn On Delay, for each amp.

Years ago I remember that a very expensive AC conditioner could do that (don't remember the brand or model), But it only had programable turn on delay, for 2 outlets. I need to sequence delay AC power to 5 pwr. amps.

I could build it myself, if I could find a schematic or PC board.

Any Ideas?

MLStrand56

[Mooly]

Ideas... use a high wattage low value resistor in series with the mains that is shorted out after a few 10's or 100's of milliseconds. Similar idea to the standard slow start for toroidal trannys.

Depends how you turn them all on of course... I'm assuming you throw one switch and they all power up.

[tauro0221]

Hi,
You can also use zero crossing SSR and turn each one in sequence in delay using a micro processor. the zero crossing SSR also prevent the inrush current. it is a simple application.

[DF96]

The thing you need is called a Power Sequencer.

[MLStrand56]

Originally Posted by DF96

The thing you need is called a Power Sequencer.

Thanks! At least now I know what to look for.

MLStrand56

[MLStrand56]

Originally Posted by Mooly

Ideas... use a high wattage low value resistor in series with the mains that is shorted out after a few 10's or 100's of milliseconds. Similar idea to the standard slow start for toroidal trannys.

I'm assuming you throw one switch and they all power up.

Actually I need a power up delay of several seconds per amp.

Yes, I turn them on with a single switch. When I lived in USA, I wired a 30 amp service to the Amp Rack, & used a 120V Contactor to switch the 30 amp service. Now I live in Philippines & rent a house. The whole house only has 5 ckt. breakers (very common here)

MLStrand56

[JMFahey]

1) just turn them on sequentially, by hand.
Not that hard to do.

2) build a board with 5 555 timers, with varying delays (5/10/15 ... seconds) each driving a 220V rated relay with enough current capability to turn your amps on safely.
Plug your amps in the outlets in this controller, and leave them always on.
Now your On-Off switch is the small one which powers the controller/sequential delay board.

Something like this will do for 1 stage.
Repeat as needed

For a fuller discussion, how_to_calculate and other cool LM555 applications:
http://home.cogeco.ca/~rpaisley4/LM555.html

[MLStrand56]

Originally Posted by JMFahey

build a board with 5 555 timers, with varying delays (5/10/15 ... seconds) each driving a 220V rated relay with enough current capability to turn your amps on safely.
Plug your amps in the outlets in this controller, and leave them always on.
Now your On-Off switch is the small one which powers the controller/sequential delay board.

The 555 timers could be controled by the Master On/Off switch!!!

I'm Intreguied(sp?)!!!!!

MLStrand56

[MLStrand56]

I found a Carvin 10 ch. AC delay sequener on E-bay for $139. The "suggested" retail price is $489. It's WAY more than I need, but it's WAY cheaper than PANAMAX, which Doesn't do what I need.

MLStrand56

[Bare]

Geee all that effort and expense .. for naught.
Learn to turn them on in groups of less than five :-)
OR fit an uprated Mains breaker, or even upgrade the Wires to the single /circuit plug you use.. for All 5 of the contraptions