Mailing List lml@lancaironline.net Message #61760
From: Stan Fields <sdfields@austin.rr.com>
Sender: <marv@lancaironline.net>
Subject: RE: [LML] Re: Contactors vs Solid State Relays
Date: Thu, 26 Apr 2012 07:49:32 -0400
To: <lml@lancaironline.net>

Thanks for the feedback about Solid State Relays vs. Contactors. After looking at the contactor specs a little closer, one huge advantage is their ability to handle higher currents for short periods and survive. For example a 60 amp contactor can handle 700 amps for 10 seconds with a 35 minute off period. This would handle the high starter surge current of the starter motor. The Solid State Relay would be toast.

 

So enough experimenting, I'll go check out the Kilovac line of contactors.

 

Stan

 

From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Colyn Case
Sent: Wednesday, April 25, 2012 3:24 PM
To: lml@lancaironline.net
Subject: [LML] Re: Contactors vs Solid State Relays

 

Hi Stan,

 

I think if you take a hammer to one of those contactors and look inside you will not be favorably impressed.

I had one fall apart on my power grid as a result of an installation error.

This caused me to look into the specs.

Here are some issues to think about:

- What is the max current at which the unit will disconnect?

- What is the coil hold current (amount to keep it closed)?

- What is the susceptibility to contact deformation....and what kind of electronic protection do I want to provide for that?

- Max # cycles

 

I ended up going with Kilovacs.  These are still mechanical.   They are expensive but quite a bit more robust.

You can look up on the web.

 

I'm sorry I don't know much about solid state relays.   I bet VP has some opinions.

 

Colyn

 

On Apr 25, 2012, at 10:19 AM, Stan Fields wrote:



I am doing the wiring of my Legacy and would like the group's advice on the use of Solid State Relays like <image002.png>SSRDC50V80A Relay Datasheet    

 

or a traditional mechanical contractor like a Cole Hershee 24115.

 

 <image006.png>

 

They are about the same cost, and handle the same load but are there other reasons why I haven't  seen the SSRs used. I am using the Vertical Power VP-X which makes extensive use of Solid State Relays so I wonder if their time has come and I should design the power distribution with SSRs?

 

Stan Fields

L2K - 201

Austin

 

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