High Voltage Switches - Which Ones Can I Use

Discussion in 'General Electronics Chat' started by DotScott1, Jun 21, 2015.

  1. DotScott1

    Thread Starter New Member

    Jun 21, 2015
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    So this is kind of a newby question but: I have a battery that's 90v @ 65 Amps (peak) and I need a power switch on it. I'm just wondering what type of switch I could actually use for this. I know it needs to be a high-voltage/amprage rated switch but... can I just go by wattage? Like, a lot of switches are rated for 120v and ____ amps. Would it work fine as long as the wattage rating is the same?... if you can't tell, I'm a little confused on this.

    Anyway, any help would be greatly appreciated. Thanks in advance!
     
  2. markdem

    Member

    Jul 31, 2013
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    Last edited: Jun 21, 2015
  3. #12

    Expert

    Nov 30, 2010
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    Close, but no cigar. The voltage rating is a survival limit. If the switch is rated for 120 volts, it will surely survive 90 volts. And, batteries are DC only. The current is what melts things. Need more information. One operation per day? One thousand operations per second? What's the load? Light bulbs? A motor?
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Is this a manual operated switch?
    When switching DC of this current you need to be aware of arc over etc, there are specially rated switches and relays with arc suppression build in.
    Max.
     
  5. DotScott1

    Thread Starter New Member

    Jun 21, 2015
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    That's exactly what I was worried about. Just need to find a switch that can handle that current.
     
  6. DotScott1

    Thread Starter New Member

    Jun 21, 2015
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    Yeah the current is what I'm most worried about. I don't know what kind of switch can handle that. And yeah probably anywhere from 1 operation a day to 1 operation every couple of days. So I guess I need something that can handle the current and is going to be reliable. It will be powering a motor.
     
  7. DotScott1

    Thread Starter New Member

    Jun 21, 2015
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    Whew, that's some heavy duty stuff. Was hoping I could find something a little smaller... and cheaper. And I guess I could look into using a relay.
     
  8. #12

    Expert

    Nov 30, 2010
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    The BATTERY is 65 amps. The MOTOR is what determines the current. I have installed hundreds of 60 amp, "disconnect" switches on air conditioners, which are mostly motors ;)
    I'm talking $30 American at Home Depot.

    http://www.homedepot.com/p/Eaton-60...d-Case-Switch-DPB222RP/100193214?N=5yc1vZbm0h

    This is not a DC switch, but...we're still negotiating.
    How many amps does the MOTOR take?
    Do you want this to last for the rest of your life? Totally legal? Just some hobby job that will be forgotten and rusting in 3 months?
     
  9. MaxHeadRoom

    Expert

    Jul 18, 2013
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    Especially if you are switching a DC inductive load, one step would be a large R/C snubber from after the switch to the opposite pole.
    If the source is also inductive, then you would use one before the switch also.
    Max.
     
  10. DotScott1

    Thread Starter New Member

    Jun 21, 2015
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    The motor can take up to 100 amps at 90 volts. In this setup, it is "programmed" to take 65 amps in 20 second intervals (and then break for around 20 seconds if the temp is too high). But I figured it out! I'm going to install a power switch into the speed controller and control it through that. Found a way to use a small, low voltage switch to power on/off the entire system :) Sorry, realized that I didn't really mention the speed controller before :x

    PS. It is legal and it is just a hobby job but not something that will soon be forgotten :)

    Thanks for the replies! Really appreciate the help.
     
  11. DotScott1

    Thread Starter New Member

    Jun 21, 2015
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    I actually figured out how to control it through a speed controller with a low-voltage switch :)

    Thanks for the replies! Greatly appreciated.
     
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