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Author Topic: 30 amp power cable  (Read 4871 times)

Michael Jone

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30 amp power cable
« on: July 07, 2011, 08:56:26 am »

I have 2 old amplifiers that have 30 amp power cables, is there a safe way to get these to 2 15 amp cables or something similar?
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john sanders

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Re: 30 amp power cable
« Reply #1 on: July 07, 2011, 09:33:22 am »

Yes, since these plugs are 110 volts you can simply change the plug to a 15 or more preferable 20 amp. Obviously the performance of the amplifier will be somewhat compromised however this is done quite often with many older Crown/Crest amplifiers.
 
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Tim McCulloch

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Re: 30 amp power cable
« Reply #2 on: July 07, 2011, 12:16:23 pm »

I have 2 old amplifiers that have 30 amp power cables, is there a safe way to get these to 2 15 amp cables or something similar?

As you posed the question, the answer is "no."

If you want to change the connectors to a 15 amp or 20 amp Edison plug, feel free to do so... but make sure the outlet is protected by a correctly rated breaker, i.e. don't wire up a 15 or 20 amp receptacle to a 30 amp breaker.

Be advised that running those amps at 1/3 duty cycle WILL trip a 20 amp breaker.  If you need to run them that hard you need to get "real" power service for them.
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"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Alan Sledzieski

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Re: 30 amp power cable
« Reply #3 on: July 07, 2011, 06:28:11 pm »

I have 2 old amplifiers that have 30 amp power cables, is there a safe way to get these to 2 15 amp cables or something similar?

What kinda amps are they?
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Marlow Wilson

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Re: 30 amp power cable
« Reply #4 on: July 07, 2011, 09:56:53 pm »

As you posed the question, the answer is "no."

If you want to change the connectors to a 15 amp or 20 amp Edison plug, feel free to do so... but make sure the outlet is protected by a correctly rated breaker, i.e. don't wire up a 15 or 20 amp receptacle to a 30 amp breaker.

Be advised that running those amps at 1/3 duty cycle WILL trip a 20 amp breaker.  If you need to run them that hard you need to get "real" power service for them.

+1, but to add anecdotal advice it can be done.  Some time ago I swapped out a pair of bridged amps at my little venue to optimize what we had available within budget in the short term.  The two bridged amps were RMX 2450's, replaced by single 9001.  The 2450's each had a 15 amp circuit (20 amp circuits are less common in Canada...) and so we had to pull the 30 amp twist off the 9001 and replace it with an edison.  I was nervous! 

One year and many shows later I forget it's there.   It's never caused an issue on startup, and we have lots of rig for the gig with adequate limiting so the signal the amp is getting is under control.   DJ's with Dubstep or Death metal, it's lived through them all.  Is this the right thing to do?  NO!  I'm only sharing my story that it can work (it may not work - no warranty is expressed or implied).  Note that our subs (Turbo TSW 718) are 4 ohms nominal, but they are really less.

Impedance matters....
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Bob Lee

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Re: 30 amp power cable
« Reply #5 on: July 18, 2011, 07:24:07 pm »

I have 2 old amplifiers that have 30 amp power cables, is there a safe way to get these to 2 15 amp cables or something similar?

If you don't know what amps you have, then the answer is "no."

If the amps are made to have 15A plugs and cords but for some reason have 30A, then it can be done. Consult the manufacturer.

Regarding one thing that was mentioned in an above post: Putting a lower rated plug and/or cord on an amp will not compromise performance (after all, the plug and cord do not somehow throttle back the power to keep the current under 15A), but they may cause you to trip a circuit breaker when you don't expect it. And it is not as safe as having proper power cabling and connections.
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David Parker

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Re: 30 amp power cable
« Reply #6 on: July 18, 2011, 09:42:16 pm »

I have 2 old amplifiers that have 30 amp power cables, is there a safe way to get these to 2 15 amp cables or something similar?

the manual for the amp should list the actual power draw at different loads. Usually the only time the amp draws anywhere near 30 amps is running bridged mono with a 4 ohm load. I had a couple of crown MA3600 amps years ago that had 30 amp plugs. As I recall the amp only drew 16 amps @ 4 ohms stereo, typical music. If you switch it to a 20 amp plug, most wall outlets wont accept it, because most wall outlets have 15 amp receptacles. You can plug a 15amp plug into a 20 amp receptacle, but not the other way around. If the receptacle has the proper sized breaker, theoretically you can't hurt it, but you might trip the breaker.
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Albert Thomas

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Re: 30 amp power cable
« Reply #7 on: July 19, 2011, 12:26:38 am »

I have 2 old amplifiers that have 30 amp power cables, is there a safe way to get these to 2 15 amp cables or something similar?

What I think you mean is to split each amplifier supply into two 15 amp standard plugs. This could work ONLY if you plugged them into two different 15amp circuits that were on the same side of the 240V circuit. If they weren't,  you'd trip the breaker but probably not before letting the magic smoke out of your amp :(

I you're inquisitive, just wire one 15 amp cord up, plug into a 15 amp circuit and put an Amprobe on it while you slowly crank a LF warble tone into some subs that can handle the max. output of the amp and see how much 15 amps will deliver to the business end. Should be good for at least 1kw at the cones before the breaker quits, (unless it's a class A amp).
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Tim McCulloch

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Re: 30 amp power cable
« Reply #8 on: July 19, 2011, 01:47:46 am »

I have 2 old amplifiers that have 30 amp power cables, is there a safe way to get these to 2 15 amp cables or something similar?

What I think you mean is to split each amplifier supply into two 15 amp standard plugs. This could work ONLY if you plugged them into two different 15amp circuits that were on the same side of the 240V circuit. If they weren't,  you'd trip the breaker but probably not before letting the magic smoke out of your amp :(

Dangerous and a violation of the NEC.  DO NOT ATTEMPT the actions in the bold text.
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"Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possible can. You will get an enormous reward. You will have created something."  - Kurt Vonnegut

Albert Thomas

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Re: 30 amp power cable
« Reply #9 on: July 19, 2011, 11:50:00 pm »

Dangerous and a violation of the NEC.  DO NOT ATTEMPT the actions in the bold text.
[/quote]

+1 Definitely!  I was ruminating what I thought he was proposing and what was hypothetically physically possible, but not necessarily recommended, legal, or safe.

Thanks for pointing out the hazard.
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ProSoundWeb Community

Re: 30 amp power cable
¬ę Reply #9 on: July 19, 2011, 11:50:00 pm ¬Ľ


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