[quote author=Amigo link=topic=1257.msg6782#msg6782 date=1299907211]
A 10 H/P 3 Phase motor will operate just fine on a RPC utilizing a 10 HP. Delta wound motor. In fact, a 10 HP. RPC, Delta wound, will easily run 3 or 4 more 10 HP. machines if power balance capacitors are used - a rule of thumb is 70 to 75mf per hp. recommended for each cap. Thus, a 10 H.P. RPC would need 700 to 750mf (microfarad) run capacitors. The "rule" is not hard & fast cause conditions can vary.
I've been running a 5 hp. lathe off of a 5 hp RPC since 87, with no ill effects...I eats my own cookin.
However, a 15 H.P. machine can't be run off of a 10 HP. RPC regardless of number & size of caps. used.
Turbo recently posted a link to a Lindsay Publication titled "How to run a 3 phase motor on single phase". It is a must read.
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When I saw your post here, it raised the question....how does one tell whether a motor is Delta wound or Wye wound, especially when looking on the internet? When I bought my nice NOS 5 hp 3 ph Boston gear motor on eBay last year, I had a picture of the motor plate but there is nothing on the plate to determine how the motor is wound. All that told me was the amperage at each of the two rated voltages and the wiring diagram for each voltage. (220/440)
It's a nine wire motor. T1 through T-9. I have it wired for the lower voltage with T1/T7, T2/T8 and T3/T9 together to make the needed three output wires. T4, T5 and T6 are tied together. It works fine. I guess that it's a Wye wound motor but I still am not certain.
I don't disagree with your premise that a Delta motor may have certain advantages but it's hard to tell what you are getting. Sellers never seem to have that information handy. Due to my location in a rural area, 99% of my equipment comes from internet sellers. There's lierally nothing available locally.
In any case, my 5 hp motor has more than enough power for my 3 hp mill as I mentioned elsewhere.
Curious in Northern California.