Would this transformer drive my servos ok?

[Jackal66]

Hello,

I am having trouble with the availability of the Dugong drives. Mine have been on order since March, but they do have the Whales in stock.

The power supply transformer in my Hurco now is 60 volts x ( 1.414 bridge rectifier) = 84.84 volts output.

The servo motors are 90VDC, 20A peak & 12A continuous.


Dugong drives are 160v & 35A.

The Whales are 80v & 20A.

Plus the Whales are $70 each cheaper than the Dugongs.


Would a toroid transformer like one of the following work ok?


Antek - AN-8455


Antek - AN-10455

The difference in the cost of the drives would more than pay for the transformer.

The transformer terminology is a little confusing to me. Would these I linked to have enough amperage?

Would the lower voltage really lose that much performance?

They have a brake resistor specific to the Dugong & Whale, because of the current generated by coast down. Is that a concern here?

I am just ready to get started and those Dugong drives seem to be double the ratings of what I need. Or are they?????

Thanks in advance,
JAckal

[Al_The_Man]

1kva is pushing it a bit, the transformer usually fitted to this set up is at least 1.5kva and 2 kva preferred.
Lower voltage means a lower maximum rpm.
Is that a brake resistor or a back emf suppression? you do not usually brake on a servo motor in motion, but an over voltage circuit is often used.
Al.

[Jackal66]

Al,

Here is the link to the resistor:

CNC4PC

That is something I know nothing about.

Here is a thread from earlier today where Bloke was telling me about the function of " back EMF suppression" capacitors.

http://www.cnczone.com/forums/hurco/...tml#post932784

Can you tell me in layman's terms the function of the EMF suppression and how it is wired?

So then, if I can find a transformer like those in the link with 2kva, it should work ok?

Does this mean lower voltage would give me a 10% ( + or -) power loss from what the servos were running originally?


Thanks again,

JAckal

[Al_The_Man]

Lower voltage generally means lower rpm capability.
The 3 phase suppression network such as RK Electric Co. RC Network Model RCY6A-30V
The have a star connected RC network connected across each phase to suppress high voltage spikes that may appear between phase.
Typical values are .47uf in series with 220ohm resistors.
Al.