Newbie- Router control relay

[mollytalker]

What relay is recommended to control 12 amp router with Gecko540?

[Al_The_Man]

What part of the machine do you want to control, power to drives? power to spindle?
Other?
Is this part of an E-Stop circuit?
Al.

[wildwestpat]

Hi

First problem is that the Gecko is expecting to drive a low voltage control device. Thus it is necessary to use a power relay or contactor. Whilst you could use a semiconductor relay to control the router this arrangement is NOT suitable for emergency switch off where a simple mechanical coil operated contactor is necessary to provide the certainty of a reliable switch off under all conditions. My prefference would be to use a semiconductor relay for the CNC router ON/OFF and a separate contactor for the last resort emergency switch off.

A trip to your local eletricians wholesaler should get you a suitable contactor suitable for both emergency stop as well as on/off. These are sold as DIN rail mounted contactors for control of electric motors and lighting loads and normally come as 20 or 40 amp ratings with two or four poles these are normally off type and are available with both mains as well as low voltage energising coils.

The use or rail mounting also enables circuit breakers and other mains distribution bits to be fitted neatly together in one of the many different types of plastic or metal enclosure. Rail mounts for semiconductor relay are available but suitable partitioning would be required as you would be mixing low voltage and mains in the same enclosure - the use of an intermediary relay is also possible.

Here in the UK contactors are available from £16 for a four pole 40 amp device suitable for motor switching of 2.2 Kw. The matching plastic IP66 or metal wall mounted box at another £15 with a master switch at £6 or a 32 amp RCD for £25. These components all have nice strong screw terminals.

In my opinion it is best to purchase from the local supplier rather than use relays intended for electronics or OEM. There are as Al is indicating by his question about the use some regulations about emergency stop arrangements. The emergency stop is different from but under some circumstances can be combined with the CNC ES and the circumstances are spelt out in the local regulations. Best to think of CNC ES as protecting the work and the machine from wrong motions and the emergency stop as the last resort button to hit in the event of someone getting hurt. A risk assesment is needed and this has to be quite detailed as there are often other considerations arround the bringing of the machine to a safe rest as quickly as possible.

It is always best to keep the last resort emergency switch arrangements a simple as possible and use parts intended for this use. If you need help with part numbers ask as I think both Hager and Wylex contactors are available to you locally along with suitable enclosures.

Regards

Pat

[Crevice Reamer]

Originally Posted by mollytalker What relay is recommended to control 12 amp router with Gecko540?

These 48V relays will control 240V 20A AC, but you are better off to connect this to G540 and use it to control a contactor:

http://www.newark.com/tyco-electroni...lay/dp/66F6698

CR.

[Al_The_Man]

As Pat mentioned, contactors are often the best bet as you can control multi-functions or multi power with one shot, if using the standard 4 pole 3 phase contactor, up to about 4 auxiliary contacts can also be added for any other low current function such as drive enable etc.
I have not seen Hagar or Wylex in N.A., I tend to favour the DIN style Telemecanique/Square D as they are usually plentiful and cheap on ebay.
Al.

[mollytalker]

Thanks to all for the information...