Centroid Community CNC Support Forum

so im reading the manual for the 1616 board and the table says its relays are rated for 10amps at 120vac or 5amp at 30vdc. what i'm seeing printed on the relays contradicts that information. https://www.centroidcnc.com/downloads/C ... DD1616.pdf
looking at the pcb you can clearly see the relays are all TE Pch-105d2h rated at 5amp NO 3amp NC for 277vac same amp rating for up to 30vdc. I'm wondering if centroid updated the design of the PLCADD1616 and didn't update the manual on their manuals web page to reflect the change

it appears all the relays on the board are NO/NC Pch-105d2h type its just a pcb design limitation that only allows 14 of them to be used NO and two of them to be both NO/NC. If you was in a pinch and needed to, i guess you could solder an extra NC terminal off a relay pin on any of the other 14 if you needed an extra NC.

anyone got any thoughts on this, it would be nice if the relays were all 10amp as you could run a lot more stuff straight off the board but i suspect 5amps NO and 3amps NC is the real limit. also if the older boards were 10amp rated then some people will have to be careful if their board ever fails and they need a replacement as it will be a lower rating.

The relays are rated as follows for NO contacts:
5A@30VDC resistive
5A@277VAC resistive
10A@125VAC resistive

For NC:
3A@30VDC resistive
3A@277VAC resistive
(rating at 125VAC omitted)

Relay data sheet:
https://www.te.com/commerce/DocumentDel ... ng=English

The PLCADD1616 specifications are correct for NO contacts. However, the chart should be more specific about NC contact and resistive ratings. Thanks for pointing that out.

Also notice that inductive ratings are not provided. Any inductive load should be properly snubbed and well under the resistive ratings. In practical terms, this means running motors with contactors, not PCB mounted relays.

thanks for the clarification. i did a forum search and found no other mentions so I'm guessing it just hasn't been an issue for others, im trying to do an install as clean as possible and i have a couple of circuits near the rating so i may have to piggyback some larger relays off the 1616 relays.

I try not to push the on-board relays to anywhere near their limits, especially with larger inductive loads (i.e. motors). In the event of a failure, it is a lot easier to diagnose and replace an external ice-cube relay than it is to replace the on-board relays.

You should be able to run all your contactor coils, relay coils, and solenoid coils directly from the on-board relays.

Use external relays to power your carousel motor and tool-arm motor.