Selection of AC transformer for Align Power Feed

[Dan_BParticipant @dan_b]

[Dan_BParticipant @dan_b]

Hi,

I am a bit of a novice when it comes to AC transformers so would appreciate a second opinion on my choice please.

The Align power feed unit is 110V, 90watt and 1amp so would a 150VA transformer be correct or should I go a little higher with a 250VA?

Stepping down from 240V if that makes a difference.

I was going to buy the transformer from Inverterdrive supermarket at the same time as ordering an Inverter, they appear to be a competitive price.

Kind Regards

Dan

[John HaineParticipant @johnhaine32865]

110V x 1A = 110 VA, 150VA should be plenty.

[John RuddParticipant @johnrudd16576]

Go to your local electrical factors and ask for a 240-110V AC control transformer….

Dont know your location but here's an example….

https://www.rselectricalsupplies.co.uk/chint-multi-voltage-panel-transformer-150va-ndk150_1068

[Nicholas FarrParticipant @nicholasfarr14254]

Hi Dan_B, you may have noticed the John's answer is 110 VA which means volt amps, this is because outputs are rated in volt / amps and not in watts, both of course have the same numbers in the calculation, this Transformer Rating may help you understand the reasons.

Regards Nick.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Nicholas Farr on 23/10/2021 11:10:09:

Hi Dan_B, you may have noticed the John's answer is 110 VA which means volt amps, this is because outputs are rated in volt / amps and not in watts, …

.

’though some confusion is caused by the statement that:

“The Align power feed unit is 110V, 90watt and 1amp”

… I wonder why that rating is given for [one would assume] the motor.

MichaelG.

[John HaineParticipant @johnhaine32865]

Power factor.

[Ian PParticipant @ianp]

Seems odd in this day and age that there is not a power feed unit natively designed for UK and European mains voltage.

I know some industrial equipment, like site tools, are intended for 110V operation but presumably these power feed units would be connected directly to the mains in the USA. If that is the case then a fairly small (physically) autotransformer could be used to connect them to UK mains.

I had a quick look on one sellers website and in none of the pictures is the connector on the end of the mains cable visible so its not clear whether its just bare wire ends or a USA style plug. I thought electrical appliances could only be sold with a fitted BS1362 plug?

Ian P

[Martin ConnellyParticipant @martinconnelly55370]

My align kit has a AL 201 NEMA plug.

Martin C

[Frances IoMParticipant @francesiom58905]

the 110V site transformers are true transformers – the secondary is centre tapped with a connection to earth thus maximum 55V supply which is considered safe.

[Nicholas FarrParticipant @nicholasfarr14254]

Hi, I do agree with Frances IoM, but you still get 110V across the live terminals, which can be fatal for some people, but you can only ever get 55V between any of the two live terminals and Earth, which is the most common cause of fatalities on a 230V supply. I have worked on sites where 110V transformers with the domestic 13A plug top is not allowed and an industrial blue type of plug has to be used, but many of them didn't have a 13A socket available to plug into anyway.

Regards Nick.

[Ian PParticipant @ianp]

From the Align unit manufacturers point of view making only a 110V model is easiest but it does complicate things somewhat in countries that have other mains voltages.

I know some machines have a built in 110V supply for the control gear (nowadays more likely to be 24V) but would that supply be rated high enough to drive the feed motor I wonder.

Using a site transformer (55-0-55) to drive a feed motor is overkill in terms of weight, bulk, wattage and cost. If the Align unit is intended to be connected to a mains supply then isolation should not be needed and a much smaller autotransformer will do the job.

I have never examined one of these units and dont even know what colour wires are in the power lead or whether it come fitted with a moulded on plug, The cable though (to me) looks out of place on a large milling machine compared to the usual heavy duty cable or conduit.

Ian P

[Dan_BParticipant @dan_b]

Thanks for all the responses – I wasn't sure how much 'head room' an AC transformer should have but seems my initial thoughts of 150VA are about right.

For info the Align unit I received doesn't have a plug. I presumed they manufactured them 110V for safety.

Align do sell a transformer but it was out of stock when I bought my feed from Chester a couple of weeks ago.

Regards,

Dan

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