Question
I'd like to change my Wood-Mizer 91 gas engine LT40 to electric and set it in a permanent mounting. Does anybody have experience doing this? Did the whole control panel get replaced?
Forum Responses
From contributor A:
We made the change in 1997, after trying to deal with the exhaust for a year inside. We could not find any flex tubing that could take the heat of the exhaust. We ordered from WM a Baldor E15, conversion base plate, pulley and belt. Also, the head lift chain needs to be replaced with HD chain. We did also install a new Ronk roto phase. It's rated for 50 HP. This leaves us room to expand. The saw is 15hp and the edger is 10hp.
We went from $450 min/month for gas to $50 in electric at 10/kw. Now we are at .05/kw on time of day rate.
The E25 is too heavy for your saw head. The E15 is good enough for 90% of what you saw. Plus the E15 will out-pull an Onan 24. Electric pulls full RPM till it stalls, whereas gas bogs and bogs and bogs some more, then stalls.
We just put in an order for a new Wood-Mizer LT40HDE25 Super with 25hp motor. We have single-phase power and are talking with our REA to bring 3ph 6/10 of a mile. They want more than the new mill to bring it just that far, so we are looking at rotary phase converters.
I got the electrical wiring specs for a rotary phase converter from Wood-Mizer and started calling around. Our local Crescent Electric dealer gave me a really good price on a 50kVA Ronk Add-A-Phase phase converter. Said they were having good luck with them. What has been your experience with the Ronk rotary phase converter – installation, maintenance, reliability, cause spike on line when turned on, complaints from utility, etc?
I remember reading a warning from Wood-Mizer not to remove the axle and tire assembly from your mobile mill to make it stationary. They say there is a danger it may tip over when a log is loaded or turned. Need to get a conversion kit for the leg supports to spread out the weight. Guess you could make your own outriggers but just something that may need attention.
Also, we “converted” our 96 LT40HDG35 Super to electric by finding it a new home in Arkansas and promptly calling Wood-Mizer to build us a new one with all the goodies.
It's been smooth sailing with the Ronk. When you hook up the new saw to the 3 legs, start it and check the amp draw on each leg at the saw. If one is way high or low, switch the leads around until they are as close as possible. The phase converter is well worth the investment. The best part about electrophing is hard pulling steady power.
The photo is for an idea of how to hang the cable. We used barn door roller track to carry the cable. Also, we added a rope from the saw mast the trolley so there is no pull on the cable.
One of the hardest habits to break was not starting the electric motor to put heat in the block. We switched in February and had sawn 5 years with gas. The other is a learning curve thing. Without a gasser bogging down, how hard do you feed the blade? You will hear a different sound coming from the blade when you get close to max. Yeah - the blade makes noise - you just never could hear it.
An electric edger would be nice if you don't have one.
You do need stationary legs and if you remove the axle, mount a block under the main tube where the axle was. The saw is a little tippy with big logs if you are not bolted down. We have radiant floor heat, so we are not bolted down.
Also, Ronk sends extra capacitors for starting. I don't remember the directions but we unhooked one or two to fine-tune the system.
We are 9 miles from the substation, and sometimes the power is weak at 108 v. per leg. You can feel it in the saw, so it's break time. It comes back up within an hour or so. The only maintenance we do is blow the dust out weekly. I've been told they don't like the cold. Ronk has a good technical staff.
Lucky for us, the power company installed 3 phase at no cost. There were existing transformers about 100 yards away. If I could find it, I would use used equipment as much as possible. We went to a sort of salvage place in Henderson, KY and saved $400 on a starter. I talked to WM during the changeover, and they were very helpful, even though I wasn't using any WM parts for this.
The variable frequency drive and the soft start controls currently list for $3000 each from W.W. Grainger. They require 3 phase inputs. I would question if they will operate from a phase converter. The phase converters do not have a balance 3 phase output. (They do not have 120 degree equal voltage outputs.)
If I were going to install a motor using a converter, I would get a motor that could be wired to start as a wye and a delta to run. This would reduce your starting current. To tell how your saw is cutting, install a current transformer in one leg of the 3 phase and read the amperage. If you are drawing so much power that the line voltage is below 200 volts, your motors will overheat and have a short life. You should consider going to a diesel engine gen set.
Comment from contributor D:
In regards to the note about the torque of an electric motor and how it reacts to a load until it stalls, there is little reason for any electric motor to overload, unless a tooth gets snagged or you’re not running the proper load monitoring equipment.
In addition to electric being better, it’s also easier to take measurements on load dynamically while cutting. You can clamp on an AMP meter looks like a C shaped device that closes around a lead. With manufacture knowledge of how many amps are drawing when the system is about to overload you could easily set up a signifier either overload solid state or hydraulic instant backup or a simple light bulb that lights when your getting close to overloading for when your operating the saw manually. You could even set up a number of warning lights green for good. yellow for getting close, and red for pull back now. That way you will be able to insure your motor lasts longer.
