Speaker Spike when switching power

[Zulu]

I've just checked out the pumps we're using.

The 1st pump is a "hose lock" pump bought recently from B&Q, the ".1500 Fountain & Waterfall Pump, 5010646035736"Looks 1500 l/hour, 33 Watts. This is the one on the revolve, plugging/unplugging.http://www.diy.com/n...0?skuId=9228209

The 2nd pump is ( sorry about the size of the photos !! Maybe blueroom will re-size them) ......

I haven't found a link for this model, but maybe you can see what is needed.

I have Strand Act6 dimmers.

Thanks for looking at this.

Zulu

[Brian]

I found it odd that no-one has suggested the correct answer - sort out the problem with the sound system. Something somewhere is unbalanced.

[Robin D]

That's a different issue. When you said 2 x 1600W I think we all assumed you were switching ~ 6 amps and possibly 12 if both on the same switch. I can't follow your link for the second, but the first is only 33W so is tiny.

 

Sorting out the sound system (as suggested by Brian) is therefore the appropriate way forward.

 

The pumps may well work on a dimmer snap basis, but you would a significant additional load (blues in the wings) on the dimmer channel.

 

Edit to credit Brian

[Zulu]

Thanks to Robin and Brian. Not having a skilled "sound" bloke at our theatre, "sorting out the sound system" is a bit of a problem. No-one here knows what " balanced" means!http://www.blue-room.org.uk/public/style_emoticons/default/rolleyes.gif

Our powered speakers are fed with 2 XLR cables, 1 left, 1 right. Is that balanced?

Its also been suggested that I drive the pumps off an on-line UPS, which means the pumps run on an independent (different phase) supply. Might give that a go.

Many thanks, Zulu

 

[dbuckley]

I found it odd that no-one has suggested the correct answer - sort out the problem with the sound system. Something somewhere is unbalanced.

As you'll well know, when we get the earth loop questions I'm the first to growl "stop blaming the lighting and fix the sound rig". But this kind of interference is different, and can cut straight through even perfectly configured and well behaved sound system.

 

 

I've just checked out the pumps we're using.

These are very different to what the original posting mentioned, the first pump is 33w, not 1600w as stated. These are tiddlers.

 

What I'd recommend is that you try these on the dimmer, but you'll require a 60W light bulb (often called a ghost load) in parallel with the pump, or the dimmer and pump will probably both be grumpy. This isn't an approach without risk, you could destroy the dimmer or the pump or both, but I think the risk is low, and certainly I'd be happy to try this with my dimmers.

 

Keep the 60W lamp across the dimmer outlet all the time, so you unplug just the pump, not both the pump and ghost load. Leave the ghost load connected at all times.