Centroid Community CNC Support Forum

Chevy427z wrote: ↑Sun Jul 25, 2021 1:02 pm Working on my E-Stop. I was about to order a contactor, with installed snubber, but I can not find it listed in Centroid's online catalog.

From the instruction manual:
Centroid recommends using a Scheneider Electric/Telemecanique LC1DT40B7A or similar device for the E-stop contactor
(Centroid PART# 14374). This Contactor includes snubber assembly and uses 24VAC to control it. Both the VM- and VM+ go
through the E-stop contactor.

Can someone please provide a link to it? If they have discontinued it, where do you recommend that I find one? Thanks.

Mark

https://www.centroidcnc.com/centroid_di ... nents.html

Thanks Marty.

I must be blind. Still not seeing it. I have found that page a hundred times, and the picture of the contactor with the snubber installed. The snubber has a part number (1819) and shows up in a search, but the contactor does not (14374 - from the install manual).

Mark

Chevy427z wrote: ↑Sun Jul 25, 2021 2:14 pm Thanks Marty.

I must be blind. Still not seeing it. I have found that page a hundred times, and the picture of the contactor with the snubber installed. The snubber has a part number (1819) and shows up in a search, but the contactor does not (14374 - from the install manual).

Mark

Scroll down toward the bottom. Contactor is 6th item up from the bottom of the page

I don't know how to make myself any clearer. Have you actually read that description of what you posted? If you click that link, it puts a snubber in your shopping cart, which I have already done earlier (times 4) in anticipation of using them later. I am looking for the contactor itself. I guess I will have to go elsewhere for that. Thank you for trying.

Mark

Chevy427z wrote: ↑Sun Jul 25, 2021 2:39 pm I don't know how to make myself any clearer. Have you actually read that description of what you posted? If you click that link, it puts a snubber in your shopping cart, which I have already done earlier (times 4) in anticipation of using them later. I am looking for the contactor itself. I guess I will have to go elsewhere for that. Thank you for trying.

Mark

Sorry Mark,
My apologies, you are correct, it is for the snubber only.
Are you using 24VAC for the coil?
Marty

Just get one from Automation Direct. It will be less expensive anyway.

polaraligned wrote: ↑Sun Jul 25, 2021 6:06 pm Just get one from Automation Direct. It will be less expensive anyway.

Are they rated for high DC voltage?
Good to know if they are.

martyscncgarage wrote: ↑Sun Jul 25, 2021 6:23 pm

polaraligned wrote: ↑Sun Jul 25, 2021 6:06 pm Just get one from Automation Direct. It will be less expensive anyway.

Are they rated for high DC voltage?
Good to know if they are.

You have to find one that is correct for the application. I just pointed to Automation Direct as a potential source.
Centroid used to supply Schneider LC1 DT40 contactors which don't have a DC rating. Finding DC rated contactors is very hard because high current DC motors are not common. You can use an AC rated contactor as long as it is rated well over what you will be using it with DC. Problem with inductive load DC is that it doesn't have a zero crossing so it tends to draw an arc. DC contactors are faster to switch and have beefier contacts for a given rating which helps them break the arc cleanly. You can use an arc suppression device on an AC contactor to quench that arc. That said, if we are speaking of switching DC here, I use a Fuji AC rated contactor on my machine which switches 110vdc. My contactor is AC rated to 600v and I think 50 or 60 amps. Zero issues after 10 years of use with no arc suppression on it. Just giving a data point here....I am not making a recommendation.

I had the conversation with Eaton/Moeller Applications Engineer. Their DIL and XTC contactors are rated for DC.
I'd like to hear from Marc (cncsnw) as to which he uses.

If you have a spare main contact on the contractor, run both DC- and DC+ through each to spread the load.

Centroid will sell their contactor, bit I found out it's quite expensive (about $350) so many source their own.

Marty, there are literally dozens of contact ratings that cover both AC and DC loads, and all the variables of those loads. Those Eaton units might be good choices as long as the unit is rated for inductive loads. Using 2 contacts for the servo supply line is a good idea, I like that. The arc will break a little quicker as the motor back EMF unloads. Anyway, as stated, I am not making any recommendation but sharing what Centroid supplies and my own experience. If my contactor lasts 50,000 cycles instead of the rated 100,000 cycles, I am a happy camper. I pointed to Automation Direct as they may have a suitable contactor. On previous Mach machines I used a solid state relay for the servo power and I have to say they work sweet.