Bridgeport Manual to CNC conversion...

[John S]

Yes that's fine Dave, hard to tell what someone envisages just from a picture

[Davek0974]

Of course, no worries ;)

A rough idea of the safety/control side of the wiring...

[John S]

Sir,

Sir,
Query please?

You show pin 14 from the XPS as going to relay 1, relay 2 and the coil of K3 but you are also showing K3 across Y1 and Y2 ?

[Davek0974]

K3 controls power to the servo drives, the N/C contact on the XPS monitors the K3 unit, if it is jammed or fails to open, the XPS does not pull in and Mach will stay in reset as well as no spindle relay/contactor supply.

If K3 jams on despite pressing the E-stop or limits, it will not latch-in again.

It was a reasonable safety enhancement i think.

As with all systems, a catastrophic failure - in this case K3 welding shut on one or more lines will still leave a danger but the chances of a contact weld at these low currents is pretty rare i think?

[m_c]

You do realise that a standard contactor is designed so that if one contact welds shut, the others will still open?

[Davek0974]

Interesting, would the carrier still lift the aux contact block though? On these Sirius range of contactors, the monitoring/feedback contacts are by way of an aux contact block mounted on top.

The XPS will not work without an N/C pair on one of the output channels.

[m_c]

I never realised the XPS was through a NC contact.
It'll depend on the spec. Some will be designed so the contact closes regardless, others will hold it open. On larger contactors, you can normally wedge a small screwdriver in and close a single contact, which would then let you see if the NC contact opens or not, however smaller contactors are usually far more enclosed.

Having said that, at the currents you're working with, the contactor should never weld shut, so I wouldn't worry about it. Even if it was to stick and maintain full power, the power being maintained should not be the sole reason if the machine wasn't to stop during an e-stop.