Centroid Community CNC Support Forum

yeah i love those contactors that have the clip-on snubber/quench arcs, looks more professional in the cabinet as well.

cnckeith wrote: ↑Thu Nov 11, 2021 4:13 pm yeah i love those contactors that have the clip-on snubber/quench arcs, looks more professional in the cabinet as well.

Yup, that's exactly what these are. Nice and neat. Another thing I love is that many of the contactors had auxiliary switch blocks snapped on the top of the contactor and some are NO and some are NC. They come in handy to send signals elsewhere in the system where needed.

martyscncgarage wrote: ↑Thu Nov 11, 2021 11:39 am Certainly you can follow DMM's recommendations, but for 1KW Drives/Motors, I use ONE properly sized EStop Contactor, and ONE EMI filter feeding the logic voltage to the drives. Also one properly sized Line reactor feeding motor power to the drives maybe helpful.
My .02 based on previous experience.
Acorn System Schematic is a good general guide as well.
Marty

I'm a little surprised also at the number of contractors and filters DMM is recommending. Also their capacity's seem a little high too. I just purchased a 3-axis kit, Nema42 1.3 kw motors with DYN4 drives. Retrofit will be on a Bridgeport Boss5. Original incoming power to the machine is 3ph , 20amp fused at shut off.

I plan on wiring the drives 3 ph. DMM recommends 20 amp breakers and contactors to each drive. Motor plates indicate that they draw 6 amp max and drives are stamped <15 . I guess that's less than 15.

Question is : should I upgrade the incoming shutoff wiring and fuses to 30 amps. DMM is also recommending a 20amp line transformer to each drive or 1 30 amp to feed all three.

Tapburrbit wrote: ↑Sat Dec 25, 2021 11:30 am

martyscncgarage wrote: ↑Thu Nov 11, 2021 11:39 am Certainly you can follow DMM's recommendations, but for 1KW Drives/Motors, I use ONE properly sized EStop Contactor, and ONE EMI filter feeding the logic voltage to the drives. Also one properly sized Line reactor feeding motor power to the drives maybe helpful.
My .02 based on previous experience.
Acorn System Schematic is a good general guide as well.
Marty

I'm a little surprised also at the number of contractors and filters DMM is recommending. Also their capacity's seem a little high too. I just purchased a 3-axis kit, Nema42 1.3 kw motors with DYN4 drives. Retrofit will be on a Bridgeport Boss5. Original incoming power to the machine is 3ph , 20amp fused at shut off.

I plan on wiring the drives 3 ph. DMM recommends 20 amp breakers and contactors to each drive. Motor plates indicate that they draw 6 amp max and drives are stamped <15 . I guess that's less than 15.

Question is : should I upgrade the incoming shutoff wiring and fuses to 30 amps. DMM is also recommending a 20amp line transformer to each drive or 1 30 amp to feed all three.

This my experience:
One large contactor should be fine.
Make sure you use a Line Reactor with DMM Drives. (Ok to get one line reactor sized appropriately for the 3 drives) automationdirect.com sells them Put it on the line side of the contactor. From the contactor feed EACH DYN4 do not daisy chain.
You can use one line filter 220V 10A for the logic power to the 3 drives. Make sure you size the fuse to the drive logic power appropriately
Follow the Acorn System Schematic as a guide.
It would be better to put a breaker on each drive. Or size one breaker to feed the line reactor and make sure you use the correct size wiring being fed from that breaker to EACH drive.
Marty

Tapburrbit wrote: ↑Sat Dec 25, 2021 11:30 am I'm a little surprised also at the number of contractors and filters DMM is recommending. Also their capacity's seem a little high too. I just purchased a 3-axis kit, Nema42 1.3 kw motors with DYN4 drives. Retrofit will be on a Bridgeport Boss5. Original incoming power to the machine is 3ph , 20amp fused at shut off.

I plan on wiring the drives 3 ph. DMM recommends 20 amp breakers and contactors to each drive. Motor plates indicate that they draw 6 amp max and drives are stamped <15 . I guess that's less than 15.

Question is : should I upgrade the incoming shutoff wiring and fuses to 30 amps. DMM is also recommending a 20amp line transformer to each drive or 1 30 amp to feed all three.

I have not seen a manual for the DYN4 drives and I'm currently installing three DYN5 drives on a machine. In the DYN5 manual there is a diagram to use ONE contactor, ONE line reactor, ONE circuit breaker and ONE main noise filter for 3 drives. They DO NOT recommend using ONE logic filter for all 3 drives. There are a few notes on the manual page that say to install 3 separate logic filters, one for each drive. Do not share logic filters with other components it states. See manual page below. I know Marty shared his experience and has done this himself and I'm sure it worked but the manufacturer puts this info in their manuals for a reason. The logic filter is installed as close to the drive as possible for each drive. They are cheap insurance in my opinion. When it comes to noise in a CNC system you don't want it so why try something that may not work properly? I just want to share this so other can see it and and make an informed decision.

Contact DMM and ask their opinion about sharing a logic filter when doing this with the DYN4 drives.

I've had conversations with my contact at DMM and while he says my methods are ok, DMM or any other manufacturer will always be generic and conservative as they will not know the application.

Just look at the Centroid General system schematic. I follow their lead and their schematics when doing my builds. They've done the engineering design work and built MANY control cabinets, so I have no reason to distrust them.

DMM are entry level AC Drives and Servos. They have been around a long time. But there are better quality drives/motors out there. If course you'll pay for them as well.

My.02
Marty

Mary and Shawn thank you both for your reply's. I'm going to follow DMM's recommendations , one large Breaker and line reactor feeding to separate breakers ,filters and contractors to each drive. I've almost gotten all the components together and hope to start work on it soon. The machine has been stripped of all it unnecessary components.
This is my second acorn retrofit but first with servos. A couple of years ago I retrofitted another one of my boss5's keeping it's original stepper motors using leadshine drives.

Sounds great, I was sure DMM would steer you in the right direction and provide proper guidance on setting up their products for your specific system. I was given the same guidance with my new DYN5 drives. I have a large breaker supplying power to the cabinet and then to my terminal strips. Each drive has it's own CB, contactor and main noise filters. Then each drive has it's own logic filter right at each drive. This isolates everything and allows for much easier troubleshooting and maintenance. It is more components but it's what the manufacturer recommended to me as well.

Here's a pic of my electrical components for my new DYN5 drives. I was able to reuse many of the components that I stripped out of this machine for the new retrofit. The drives are mounted in another area of the machine and the logic noise filter is mounted right next to the drive. I have one more piece of wire duct to mount in this area and continue wiring the drives. There is also a CB for the Acorn power supply and the second 24 volt power supply for the sensors in this pic.