Gen Set as auxilary propulsion

[Airstream345]

Andrew, that’s amazing. Any details on the motor? Horsepower, volts/amps, duty cycle? Also curious about cooling if.

 

[AndrewAdams]

Electric aux drive

Alas, I am too far from the boat to go read the motor specs plate. The genset wiring to the panel carries up to 7.5kW of 120V electricity on a single leg. I was told not to try and run much else off the genset when using the electric drive. So I assumed the motor uses most of the 7.5kW 120V output. That translates to about 10HP applied to the shaft.

I think it's possible that the separate wiring to the electric drive is 240V, since it looks difficult to buy such a large AC motor that takes 120V. But the control switch looks like a garden-variety lightswitch, not the relay or contactor that I'd expect to see controlling a 240V circuit. Now that I think about it, I really ought to know this! There have been other systems more needy than this one.

On the main, I generally cruise at 1600rpm, 6.5kts, while burning 1.25gph, so the main is theoretically producing about 25hp at that rpm. (1 gallon of diesel per hour is about 20hp produced). Somewhat less than that would be applied to the prop shaft, of course. So, 20HP maybe equals 6.5kts.

I troll at engine idle, around 650rpm, about 3.3kts, which is faster than ideal for salmon but we catch them. I don't think I'm getting 10HP to the shaft at idle. So four or almost five kts on the 10hp electric doesn't seem beyond the realm of possibility for a full-displacement hull that leaves very little wake.

I've heard of other owners who put in simple electric-motor controls to get slower speeds for trolling and docking, and even reverse. Sounds neat.

Willard thought of themselves as a long-distance cruiser maker, since the 30, 36, and 40 are all ballasted hulls. The 30 has cruised to Bermuda, the 36 to Hawaii. I don't think they would have installed anything that couldn't be run for many hours. You can see the cooling fins on the motor. Perhaps this summer, on a calm day, I'll let it drive me for a while and see how warm the e-drive gets. It would be a better test than what I've carried out so far at the dock.

One downside of having the electric drive is that one feels obligated to keep a larger genset than necessary for the PNW. I'm spending 14K putting in an 8KW Northern lights, because the 1970's Onan MDJE has not been reliable. That sum would buy enough 48V solar and LFP batts to allow many quiet days on the same anchor. And I could have used the space taken up by the genset and 12V batts for a washer/dryer combo. But, as we know, every boat and system is a compromise among competing priorities.

Andrew

 

[KnotYet]

If your get home makes 10 Hp, that's 60 amps at 125 VAC or 30 amps at 240 VAC.
That light switch is only good for 15-20 so either the motor is about 3 Hp or there's
a relay/contactor somewhere?

 

[DDW]

That looks like a TEFC motor (Totally Enclosed Fan Cooled), often they are rated for continuous duty up to a certain ambient.

I am also curious as to what the name plate says. Maybe you could post a picture of the name plate at next opportunity?

 

[AndrewAdams]

Electric Motor NamePlate

Yes, I'll post an image of the nameplate or specs plate on the electric motor as soon as I can. And look around for a contactor controlled by that lightswitch. And get some multimeter readings so I'll know what I've got before I have to use it in real life.

 

[Island Cessna]

Yes, I'll post an image of the nameplate or specs plate on the electric motor as soon as I can. And look around for a contactor controlled by that lightswitch. And get some multimeter readings so I'll know what I've got before I have to use it in real life.

Your old generator and the motor are 3 phase. Be sure the new generator is also. You can also get a single phase to variable frequency 3 phase converter, but for 7 1/2 hp probably not cheap. Bill

 

[twistedtree]

Your old generator and the motor are 3 phase. Be sure the new generator is also. You can also get a single phase to variable frequency 3 phase converter, but for 7 1/2 hp probably not cheap. Bill

You think so? I sure would make sense for the electric motor, but I haven't heard of a 3 phase generator that small. But maybe I just haven't heard of one.

 

[mvweebles]

I too was surprised when Andrew said Patience had a single phase generator. My understanding was Willards get home atrangement was a 3-phase setup with massive 5hp electric motor weighing a couple hundred lbs. As TT hints, the 3-phase generator was large, something along the lines of 12kw which makes it oversized for regular use on a W40, predominantly a West Coast boat.

BTW - Patience is Hull #1 of the W40 lineup, the very next boat Willard built after completing Weebles, the last hull of the W36 line. I'll be curious to get an update on what is installed.

Peter

 

[Bmarler]

I have an old mdje 7.5 kw onan and it’s a single phase genset. Mine seems pretty reliable so far, but I don’t actually use it much.
Single phase vfds are a lot cheaper than they used to be, and the control you’d get by going that route would be worth it. Variable speed fwd and rev instead of full power fwd only.

 

[DDW]

A VFD for 7.5 or even 10 hp isn't all that expensive (< $1500). Far less than the difference between a single phase and three phase generator. And it would give you the ability to start, stop, and change speed with push buttons or a dial.

 

[sunchaser]

If a diesel engine fails, no matter if you have a single or twins. The problem is most often fuel. So if you have some bad or dirty fuel your genny will fail Pete

Rather than argue this oft repeated notion it is best to focus on what really stops a boat. First, for most of us dirty fuel is a long ago thing of the past if one is careful. But an old dirty filter, bad lift pump or air in fuel lines are maintenance items. Secondly, water in the fuel is largely a maintenance issue whether bad “O” rings or a leaky fuel cooler.

Maintenance 101 on all systems will keep your boat going. A read of bostdiesel or Seaboard sites yields
a treasure trove of problem areas and solutions. Keep you fuel systems well tended then go onto the many nexts of potential shut down areas.

Oh, don’t run aground or out of fuel either. I’d betcha PSNeeld towed a few of those guys back to Port.

 

[AndrewAdams]

I have an old mdje 7.5 kw onan and it’s a single phase genset. Mine seems pretty reliable so far, but I don’t actually use it much.

I'm glad yours has been reliable; I've had issues with control boards, voltage regulators (takes a long time to make toast at 40V!), starters, the oil pressure cutoff, etc. Finally decided to toss it overboard.

Since the electric motor started right up when tested, I haven't spent much more time with it. Worked on the cantankerous stuff instead.

But I did wire in an auto-transfer switch between the genset and the panel, so I could easily integrate a big inverter. That circuit and the shore power are certainly single-phase 120V. So, if I have a three-phase genset, I'm only using one leg and wouldn't that put it way out of balance? Doesn't seem like the previous owner and his Dad, who spent a lot of $ on redoing the panel with a fancy Blue Sea Systems, would have gone in for a flawed design.

I look forward to getting to the bottom of this.

 

[rpackard]

I am the owner who installed a variable frequency drive controller on Lilliana, my recently sold Willard 40. I recall that the Pisces generator put out 3 phase 220VAC or 208. I also recall that the electric motor was speced at 7.5hp. With the VFD, (which cost around $700 about 8 years ago) I can adjust the speed from 0 to +/- full speed. This is especially nice when the AC motor is started. Without the VFD the generator tries to start the electric motor at full speed immediately. This made the cog belt slip.

I recall that in flat water we could drive just a bit above 4k.

Unfortunately that huge generator is as loud as the main Perkins engine. We never had to use it in an emergency and only put a few hours on the generator in our 15 years of ownership. That use was juts to test it each season.

Another downside of this auxiliary drive is that it makes removing the prop shaft more difficult. The large cog belt pulley need to be removed and that is not easy.

Richard P

 

[widebodywillard]

gen set as auxilary propulsion

I own a 40' Willard (hull #2) which has the original gen. set and get home motor. The generator is an Onan MDJE wired to supply 208 volt 3 phase to the get home motor and 120 volt single phase to house.

 

[TowLou]

The old onan 7.5kw were a 12 wire alternator head. That would give you 120/208 3 phase vs 120/240. Good old iron and reliable them JB's and mjbs just needs a little mechanical love from time to time. See a lot of them in basements still in service.

 

[rslifkin]

I'll second the old J series Onans being available in both a 4 wire and 12 wire gen head. The 12 wire one could be configured for a whole bunch of output setups including 3 phase. The 12 wire head came in both a standard and extended stack version. The extended stack could give the full rating in single phase, the standard stack couldn't. I'd bet Willard used the extended stack units so that they could wire for 120/208 3 phase and pull the house loads off 2 of the 3 phases while still being able to load the unit fully. Unless the gen was sufficiently over-sized, then it wouldn't have mattered.

As far as a new generator, I'd definitely go single phase and use a VFD to drive the 3 phase motor. Much more practical than a 3 phase genset both in terms of genset selection and distributing onboard 120v loads.

 

[Cold Duck]

OK, I'll just "skirt" the twin engine debate here for a second, (without getting into it).

If a diesel engine fails, no matter if you have a single or twins. The problem is most often fuel. So if you have some bad or dirty fuel your genny will fail also.

pete

I have had 2 damper plates fail over the years, one on a Perkins 4-108 in the Willard, the other on an Izusu aux with a 40ft ketch. Willard had to be towed to port, ketch sailed into San Diego Bay and towed to Customs dock. Neither case was fuel an issue and an aux drive would have been very helpful. These were non catastrophic engine failures, but disabled the main drive non the less.

 

[AndrewAdams]

My boat guy is on the boat today and he said his look at the wiring leads him to think the old MDJE Onan is outputting 120VAC to the panel and 240VAC to the electric motor.

It's my impression that this is still referred to as "single-phase" as you have two 120V legs in the same phase but with opposite voltages.

Since these early Willards were hand-built one at time, they may have been experimenting with different setups at the time.

Attached is the plate from the old genset. He is indeed going to have to fiddle with the gen-head wiring to make sure it will drive the panel and the get-home.

Andrew

 

[AndrewAdams]

I own a 40' Willard (hull #2) which has the original gen. set and get home motor. The generator is an Onan MDJE wired to supply 208 volt 3 phase to the get home motor and 120 volt single phase to house.

Saw your boat in Sitka last summer - looked great! Nice dinghy crane setup, with the pipe base on the gunwale.

 

[KnotYet]

Pretty sure that ID plate shows P.H.3 and wiring for 3 phase.
5.5 kW/ 4kW

 

[Island Cessna]

My boat guy is on the boat today and he said his look at the wiring leads him to think the old MDJE Onan is outputting 120VAC to the panel and 240VAC to the electric motor.

It's my impression that this is still referred to as "single-phase" as you have two 120V legs in the same phase but with opposite voltages.

Since these early Willards were hand-built one at time, they may have been experimenting with different setups at the time.

Attached is the plate from the old genset. He is indeed going to have to fiddle with the gen-head wiring to make sure it will drive the panel and the get-home.

Andrew

I think post #46 above has your generator described accurately, and the nameplate you show is on the motor not the generator.

I had a good look at your boat in 2012. The generator and motor then were for sure 3 phase, the motor starter is mounted on the bulkhead just aft of the rear engine room access hatch, with its coil powered from that light switch.

Post #46 also gives you good advice if you do have to change to a single phase generator. A modern single phase to three phase Variable Frequency Drive (VFD) will give you soft start, speed control, and reverse. It will take lots of single phase amps to power it!

Bill

 

[Bmarler]

It only takes a glance to see that the motor is three phase. If your boat guy didn’t see that you might not have the right guy for this particular job.
I think a vfd is definitely in your future. It’s a far superior way to control the motor anyway.

 

[AndrewAdams]

I agree, there's a lot of info out there to help me learn about hooking up this 3-phase motor to a VFD, without having to fiddle with rewiring the generator head. Thanks, everyone, for setting me straight!

 

[KnotYet]

Of interest probably only to me, FFD motors is still in business
and could still supply a similar motor.

 

[TowLou]

That is 3 phase output there. Can even get 480/277 out of it.

 

[widebodywillard]

When we bought our boat the get home motor had been removed but was in a pile of misc. stuff that "comes with the boat". I liked the idea of having a get home system so reinstalled it but had no idea how to connect the wires for three phase. The wiring from the gen set to the switch box was still inplace (start,stop,reset) and was told I only needed to connect the three wires from the motor to the three post in the switch box, easy. If the motor ran in the wrong direction, take any two of the three wires and switch them around. This is what I did and it worked.

So, I think if your gen/motor is 3 phase, you will have 3 hot wires connecting
them. If single phase, only two hot 110 volt wires combined for 220 volts single phase. I might be all wet, but that might be a simple way to determine whether your system is three phase or single phase.

 

[Airstream345]

I for one would love to see more photos of the systems overall, specifically the motor mount, pulley systems, belts, etc. We have a HUGE 20Kw Onan generator onboard and I've explored all sorts of get home options (in addition to our sails)

 

[AndrewAdams]

Pictures of Electric Get-Home Emergency Drive

OK! I'm on the boat and have found that half of what I thought I knew about my E-Drive was wrong. I've followed some wiring and taken some pictures. Boat is a single-engine Willard 40 with a Perkins 135 and (new to me) a NL 8kW genset. It shipped with a 7.5kW Onan that I've just taken out.

The genset is wired to send 120V single-phase to my AC panel and 208 3-phase to the emergency drive. I've attached a photo of a page from the manual about how to do this with this genset.

---------------
Edit - this page is actually from an Onan Manual:

https://onan.xmsi.net/900-0184 Onan YD Generators & Controls Major Service manual (10-1975).pdf

Perhaps it's the same powerhead, or there's a lot of commonality.
---------------

So, if you want to use the electric drive, first, start the genset.

You'll see in one photo that there are three belts that were put around the main shaft. Not easy to change these, of course, without disconnecting a coupling. One puts these three belts in their grooves on the electric motor and in the much larger pulley fixed to the main shaft. The larger pulley, of course, is the reducing gear.

How to tighten these belts? You'll see a photo of the side of the electric motor, which is on a tabernacle mount. Using a 1/2" ratchet without a socket, one turns the large vertical bolt and this raises the electric motor until the belts are tight.

At the bridge you'll see a photo of the e-drive switch, which controls a contactor in an electrical box, both pictured, that engages the 3-phase power to the motor.

In the January 1978 Issue of "Motor Boating and Sailing," they reviewed the Willard 40 and found the e-drive good for "five honest knots." I'll update when I'm able to test this on the water. Knock on wood, the main's only failed to start once, at the dock (replaced the starter), so I've never tested this.

Questions, corrections, or requests for more images welcome.

Andrew

 

[KnotYet]

It's pretty great that it is still there and appears functional.
I agree that a VFD would make this more user friendly.

 

[Bmarler]

It pretty great that it is still there and appears functional.
I agree that a VFD would make this more user friendly.

vfd would be hugely beneficial. fwd/rev, proportional control, etc... well worth the few hundred bucks to put it in.