lml@lancaironline.net Mailing List Archive

Consider that one possible failure mode is the welding of the contacts in which case it won't matter if it is for intermittent or continuous duty. A most helpful idea is to have an "indication" circuit off the solenoid contacts to an indicator light on the panel. If the indicator light is on after starting, turn off the master switch and the engine........................

Grayhawk

In a message dated 4/26/2012 9:40:05 A.M. Central Daylight Time, jbarrett@carbinge.com writes:

Fred.

Sounds like a better choice than we’ve been using. One question comes to mind – surrounding the idea I have (is it correct?) that the starter solenoid should be intermittent because you want it to be the weak link in the starter circuit: if the starter contactors should stick, you’d have a huge amperage draw and maybe start a fire. If the contactor is intermittent, it will theoretically fail and break the contact before the starter motor burns up and catches fire or causes other damage.

Is this logic correct? If so, would the specs on this contactor from Cole Hershee still be a good choice for the starter circuit with the TSIO 550?

24059-08 UL listed

Same as 24059, but UL and CE rated.

Continuous Rating: 65A at 12V DC. Intermittent rating:750A make, 100A break. 10 sec On, 30 min Off. Circuit G1.

Thanks,
John

From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Frederick Moreno
Sent: Thursday, April 26, 2012 4:50 AM
To: lml@lancaironline.net
Subject: [LML] Re: Contactors vs Solid State Relays

Or a traditional mechanical contractor like a Cole Hershee 24115.

A friend is a marine specialist here in Australia and said that for off shore marine applications, only the Cole Hershee contactors are approved because they are mission critical. Much more expensive than the el cheapo auto store contactor I was replacing, but even the auto store guys advocated these units for experimental aircraft because the quality standards are so much higher. The auto stores stocks both types, but many commercial truck customers (we have many in town) will only use Cole Hershee. Made in the UK, I believe.

Fred Moreno