Been using a 10-gauge cord to connect my little 2kw gennie in the garden
shed to the transfer switch in the garage.

No problems in maybe 20 hours total usage and the numbers look right per
http://tinyurl.com/nvkyq32, which says the voltage drop will be 2.5% at
full load.

My understanding being that the voltage drop should be less than 5% at
full load.

Now I am going to add a second 2kw and run them in parallel. (Honda
EU2000i + EU2000i Companion). viz: http://tinyurl.com/pjwqxbp

In outage mode, the house cruises on 800-1200 watts so 95% of the second
gennie's function will be redundant backup in case there's a problem
with one unit during an outage.

But since I will have two.... why not? Then we could fire up both
during mealtimes and accommodate a toaster or a coffee maker... or the
kitchen's big microwave.

With the two units connected in parallel, the power cord interface
changes from a regular 3-prong plug to a 30-amp L5-30 twist-lock plug.

Running the numbers (Copper wire, 10 AWG, 120v, AC single phase, single
set of conductors, 100' distance, load current 30 Amps) into
http://tinyurl.com/nvkyq32, I get a voltage drop of 5.99 (4.99 percent).

Less than the 5% limit - and, real-world, not just .1% less because the
two gennies will never be putting out a full 30 amps.

I'm thinking I can keep using the current 10-gauge cord by making up an
adapter with a female 3-prong receptacle on one end and an L5-30 male
plug on the other end.

That way, one cord does it whether I use one gennie or two; cord
winding/storage remains merely inconvenient instead of becoming
difficult; and I avoid shelling out $250-$300.

Anybody see a flaw in this reasoning?

--
Pete Cresswell

Per (PeteCresswell):
Running the numbers (Copper wire, 10 AWG, 120v, AC single phase, single
set of conductors, 100' distance, load current 30 Amps) into
http://tinyurl.com/nvkyq32, I get a voltage drop of 5.99 (4.99 percent).

Correction: Looking at a photo of the actual outlet on the Companion, I
see it is labeled "26.6" amps..... so the voltage drop is 4.43% instead
of 4.99%.
--
Pete Cresswell

On Sunday, July 27, 2014 12:06:56 PM UTC-4, (PeteCresswell) wrote:
Been using a 10-gauge cord to connect my little 2kw gennie in the garden

shed to the transfer switch in the garage.



No problems in maybe 20 hours total usage and the numbers look right per

http://tinyurl.com/nvkyq32, which says the voltage drop will be 2.5% at

full load.



My understanding being that the voltage drop should be less than 5% at

full load.



Now I am going to add a second 2kw and run them in parallel. (Honda

EU2000i + EU2000i Companion). viz: http://tinyurl.com/pjwqxbp



In outage mode, the house cruises on 800-1200 watts so 95% of the second

gennie's function will be redundant backup in case there's a problem

with one unit during an outage.



But since I will have two.... why not? Then we could fire up both

during mealtimes and accommodate a toaster or a coffee maker... or the

kitchen's big microwave.



With the two units connected in parallel, the power cord interface

changes from a regular 3-prong plug to a 30-amp L5-30 twist-lock plug.



Running the numbers (Copper wire, 10 AWG, 120v, AC single phase, single

set of conductors, 100' distance, load current 30 Amps) into

http://tinyurl.com/nvkyq32, I get a voltage drop of 5.99 (4.99 percent).



Less than the 5% limit - and, real-world, not just .1% less because the

two gennies will never be putting out a full 30 amps.



I'm thinking I can keep using the current 10-gauge cord by making up an

adapter with a female 3-prong receptacle on one end and an L5-30 male

plug on the other end.



That way, one cord does it whether I use one gennie or two; cord

winding/storage remains merely inconvenient instead of becoming

difficult; and I avoid shelling out $250-$300.



Anybody see a flaw in this reasoning?



--

Pete Cresswell

Maybe I'm wrong, but I don't think you can do 30 amps. You have two
identical generators that together put out 4KW. I may be wrong, but I'm
betting that a generator that's rated at 4KW can only do that 4KW with
a balanced load, ie either 16A @ 240V or 16A on each leg supplying 120V.
In either case it's not thg 32A that you're anticipating. To do that
it would have to be supplying 32A at 120V all to one leg and I don't think
it does that, is rated to do it etc. So, I think the voltage drop is
actually half what you think it is. And even if it wasn't I'd still be
OK with the 10g.

Another note, since it's likely to come up. You brought up running these
two generators in parallel before and they can be used that way because
they are inverter type and specifically designed to allow it. You couldn't
do it with typical generators, so thought I'd point that out before you
get 6 other replies telling you that you can't hook them up that way.

"trader_4" wrote in message
...

Maybe I'm wrong, but I don't think you can do 30 amps. You have two
identical generators that together put out 4KW. I may be wrong, but I'm
betting that a generator that's rated at 4KW can only do that 4KW with
a balanced load, ie either 16A @ 240V or 16A on each leg supplying 120V.
In either case it's not thg 32A that you're anticipating. To do that
it would have to be supplying 32A at 120V all to one leg and I don't think
it does that, is rated to do it etc. So, I think the voltage drop is
actually half what you think it is. And even if it wasn't I'd still be
OK with the 10g.

Another note, since it's likely to come up. You brought up running these
two generators in parallel before and they can be used that way because
they are inverter type and specifically designed to allow it. You
couldn't
do it with typical generators, so thought I'd point that out before you
get 6 other replies telling you that you can't hook them up that way.

I am also thinking that about 16 amps is the max that can be delivered by
the generators if they are paralled for 4 kw total.

For generators in parallel, yes there are some inverter types that can be
paralleled with out any problem.

I have two generators rated at 5 kw each that just have the generators and
not inverters.. I have often wondered if they could be paralled for more
power. I know how to place them in parallel safely but wonder if they will
stay synced up for a long period of time.
Where I worked we did that all the time with motor/generator sets. As it
cost lots of money to shut down some equipment, we used motor/genertor sets
to vary the speed of some motors. We had a bank of about 20 sets, and one
spare set. We would run both in parallel for a short time and then switch
one off.

Per trader_4:
do it with typical generators, so thought I'd point that out before you
get 6 other replies telling you that you can't hook them up that way.

Per Ralph Mowery:
I am also thinking that about 16 amps is the max that can be delivered by
the generators if they are paralled for 4 kw total.

I am too clueless to explain how or why, but these things are
specifically engineered to work together and deliver 4000 watts peak and
3200 continuous.
--
Pete Cresswell

wrote:
On Sun, 27 Jul 2014 14:21:41 -0400, "(PeteCresswell)"
wrote:

I am too clueless to explain how or why, but these things are
specifically engineered to work together and deliver 4000 watts peak
and 3200 continuous.

They are inverter generators so they can lock the phases together. The
question is whether they can lockj them in a way to give you 2 120v
circuits with 240 between the outside legs. If so you are going to cut
your voltage drop in half ... but you will need a 4 wire cable.

With the proper equipment , virtually ANY generator can be paralleled with
any other . Because generators don't always run at exactly 60Hz , the key is
to link them when they are "in phase" with each other . Once linked , they
will be locked in phase , and while one may take on more than half the load
, they will stay synchronized . One thing to consider is "circulating
current" between the generators , as wall as power factors . I was an
electrician in the US Navy , and one of my jobs was to monitor and operate
generator control boards . Lots of the details are hazy after 40-something
years , but I do remember the basics .
Here's a link to a wiki that explains it very well , including a method
that only requires 3 120v light bulbs .
https://en.wikipedia.org/wiki/Synchr...ing_current%29
--
Snag

On Sunday, July 27, 2014 2:21:41 PM UTC-4, (PeteCresswell) wrote:
Per trader_4:

do it with typical generators, so thought I'd point that out before you

get 6 other replies telling you that you can't hook them up that way.



Per Ralph Mowery:

I am also thinking that about 16 amps is the max that can be delivered by

the generators if they are paralled for 4 kw total.



I am too clueless to explain how or why, but these things are

specifically engineered to work together and deliver 4000 watts peak and

3200 continuous.

--

Pete Cresswell

I was using your full 4KW number in the numbers in my reply, treating it
just like one 4KW generator. By my analysis a 4KW generator can only
supply 16 amps on any conductor. If you have only 240V loads, it delivers
16 amps. If you have balanced 120V loads it delivers a max of 16 amps,
ie 120V @ 16 amps and 120V @ 16 amps.
And if you try to do an unbalanced 120V greater than 16 amps, eg put
30 amps on just one 120V leg, I don't
think it can deliver it. Essentially you're only using part of the
generator winding at that point.

On Sun, 27 Jul 2014 12:06:56 -0400, "(PeteCresswell)"
wrote:

Been using a 10-gauge cord to connect my little 2kw gennie in the garden
shed to the transfer switch in the garage.

No problems in maybe 20 hours total usage and the numbers look right per
http://tinyurl.com/nvkyq32, which says the voltage drop will be 2.5% at
full load.

My understanding being that the voltage drop should be less than 5% at
full load.

Now I am going to add a second 2kw and run them in parallel. (Honda
EU2000i + EU2000i Companion). viz: http://tinyurl.com/pjwqxbp

In outage mode, the house cruises on 800-1200 watts so 95% of the second
gennie's function will be redundant backup in case there's a problem
with one unit during an outage.

But since I will have two.... why not? Then we could fire up both
during mealtimes and accommodate a toaster or a coffee maker... or the
kitchen's big microwave.

With the two units connected in parallel, the power cord interface
changes from a regular 3-prong plug to a 30-amp L5-30 twist-lock plug.

Running the numbers (Copper wire, 10 AWG, 120v, AC single phase, single
set of conductors, 100' distance, load current 30 Amps) into
http://tinyurl.com/nvkyq32, I get a voltage drop of 5.99 (4.99 percent).

Less than the 5% limit - and, real-world, not just .1% less because the
two gennies will never be putting out a full 30 amps.

I'm thinking I can keep using the current 10-gauge cord by making up an
adapter with a female 3-prong receptacle on one end and an L5-30 male
plug on the other end.

That way, one cord does it whether I use one gennie or two; cord
winding/storage remains merely inconvenient instead of becoming
difficult; and I avoid shelling out $250-$300.

Anybody see a flaw in this reasoning?
As long as you are never drwing 30 amps from the generator the cord
will be "adequate". If I was setting up fresh I would buy a heavier
cord - but what you have will continue to do the job.

On Sun, 27 Jul 2014 13:01:27 -0400, "Ralph Mowery"
wrote:


"trader_4" wrote in message
...

Maybe I'm wrong, but I don't think you can do 30 amps. You have two
identical generators that together put out 4KW. I may be wrong, but I'm
betting that a generator that's rated at 4KW can only do that 4KW with
a balanced load, ie either 16A @ 240V or 16A on each leg supplying 120V.
In either case it's not thg 32A that you're anticipating. To do that
it would have to be supplying 32A at 120V all to one leg and I don't think
it does that, is rated to do it etc. So, I think the voltage drop is
actually half what you think it is. And even if it wasn't I'd still be
OK with the 10g.

That is EXACTLY what paralleled inverter generators do. They parallel
synch and put out double the output of one generator into a single 120
volt line - unless they are connected "series synch" which gives you a
220/120 center tapped output which puts 15 amps max on each "leg".

Another note, since it's likely to come up. You brought up running these
two generators in parallel before and they can be used that way because
they are inverter type and specifically designed to allow it. You
couldn't
do it with typical generators, so thought I'd point that out before you
get 6 other replies telling you that you can't hook them up that way.

I am also thinking that about 16 amps is the max that can be delivered by
the generators if they are paralled for 4 kw total.

For generators in parallel, yes there are some inverter types that can be
paralleled with out any problem.

I have two generators rated at 5 kw each that just have the generators and
not inverters.. I have often wondered if they could be paralled for more
power. I know how to place them in parallel safely but wonder if they will
stay synced up for a long period of time.

They won't synch - period.
Where I worked we did that all the time with motor/generator sets. As it
cost lots of money to shut down some equipment, we used motor/genertor sets
to vary the speed of some motors. We had a bank of about 20 sets, and one
spare set. We would run both in parallel for a short time and then switch
one off.

These "motor geerator sets" were "ward leonard" drives - AC motor
running DC generator to run variable speed DC motors bu varying the
field current of the DC generator. Parallelling DC generators is not a
serious problem Parralleling AC generators is a lot of fun, unless one
of them is a synchronous generator (like an overdriven induction
motor)

On Sun, 27 Jul 2014 14:21:41 -0400, "(PeteCresswell)"
wrote:


Per trader_4:
do it with typical generators, so thought I'd point that out before you
get 6 other replies telling you that you can't hook them up that way.

Per Ralph Mowery:
I am also thinking that about 16 amps is the max that can be delivered by
the generators if they are paralled for 4 kw total.

I am too clueless to explain how or why, but these things are
specifically engineered to work together and deliver 4000 watts peak and
3200 continuous.
The inverters "link" - the pwm signal from the one inverter bank
drives the other bank as well. It is more than just the outputs
connected. In the one's I've seen the second unit (partner) is
switched to the "partner" mode instead of the "stand-alone" mode and
it picks up the synch signal from the output of the "master" to run
the inverter on the "partner". Basically the "smarts " of the partner
unit are shut off and it gets the timing signal from the master.

On Sun, 27 Jul 2014 14:31:39 -0400, wrote:

On Sun, 27 Jul 2014 14:21:41 -0400, "(PeteCresswell)"
wrote:

I am too clueless to explain how or why, but these things are
specifically engineered to work together and deliver 4000 watts peak and
3200 continuous.

They are inverter generators so they can lock the phases together. The
question is whether they can lockj them in a way to give you 2 120v
circuits with 240 between the outside legs. If so you are going to cut
your voltage drop in half ... but you will need a 4 wire cable.
Some can work in both "series synch" (240 volt CT) and "parallel
synch" 30 amp 120 volt mode.

Parallelling DC generators is not a
serious problem Parralleling AC generators is a lot of fun, unless one
of them is a synchronous generator (like an overdriven induction
motor)

https://en.wikipedia.org/wiki/Synchr...ing_current%29

--
Snag

On 07/27/2014 03:29 PM, wrote:

The inverters "link" - the pwm signal from the one inverter bank
drives the other bank as well. It is more than just the outputs
connected. In the one's I've seen the second unit (partner) is
switched to the "partner" mode instead of the "stand-alone" mode and
it picks up the synch signal from the output of the "master" to run
the inverter on the "partner". Basically the "smarts " of the partner
unit are shut off and it gets the timing signal from the master.


Would that make it single-phase 240 or two-phase 240?

On Sunday, July 27, 2014 3:25:32 PM UTC-4, wrote:
On Sun, 27 Jul 2014 13:01:27 -0400, "Ralph Mowery"

wrote:





"trader_4" wrote in message

...



Maybe I'm wrong, but I don't think you can do 30 amps. You have two

identical generators that together put out 4KW. I may be wrong, but I'm

betting that a generator that's rated at 4KW can only do that 4KW with

a balanced load, ie either 16A @ 240V or 16A on each leg supplying 120V.

In either case it's not thg 32A that you're anticipating. To do that

it would have to be supplying 32A at 120V all to one leg and I don't think

it does that, is rated to do it etc. So, I think the voltage drop is

actually half what you think it is. And even if it wasn't I'd still be

OK with the 10g.



That is EXACTLY what paralleled inverter generators do. They parallel

synch and put out double the output of one generator into a single 120

volt line - unless they are connected "series synch" which gives you a

220/120 center tapped output which puts 15 amps max on each "leg".


I don't see why paralled generators would be paralled into just
one 120V line. Seems more logical to just parallel both legs. If you
can parallel one, why can't you parallel both legs? And regardless,
it doesn't change what I posted about his voltage drop issue, ie
the amperage on the conductors being 16A max, which is half of what he
thinks it is.

On Sunday, July 27, 2014 3:17:32 PM UTC-4, wrote:
On Sun, 27 Jul 2014 12:06:56 -0400, "(PeteCresswell)"

wrote:



Been using a 10-gauge cord to connect my little 2kw gennie in the garden

shed to the transfer switch in the garage.



No problems in maybe 20 hours total usage and the numbers look right per

http://tinyurl.com/nvkyq32, which says the voltage drop will be 2.5% at

full load.



My understanding being that the voltage drop should be less than 5% at

full load.



Now I am going to add a second 2kw and run them in parallel. (Honda

EU2000i + EU2000i Companion). viz: http://tinyurl.com/pjwqxbp



In outage mode, the house cruises on 800-1200 watts so 95% of the second

gennie's function will be redundant backup in case there's a problem

with one unit during an outage.



But since I will have two.... why not? Then we could fire up both

during mealtimes and accommodate a toaster or a coffee maker... or the

kitchen's big microwave.



With the two units connected in parallel, the power cord interface

changes from a regular 3-prong plug to a 30-amp L5-30 twist-lock plug.



Running the numbers (Copper wire, 10 AWG, 120v, AC single phase, single

set of conductors, 100' distance, load current 30 Amps) into

http://tinyurl.com/nvkyq32, I get a voltage drop of 5.99 (4.99 percent).



Less than the 5% limit - and, real-world, not just .1% less because the

two gennies will never be putting out a full 30 amps.



I'm thinking I can keep using the current 10-gauge cord by making up an

adapter with a female 3-prong receptacle on one end and an L5-30 male

plug on the other end.



That way, one cord does it whether I use one gennie or two; cord

winding/storage remains merely inconvenient instead of becoming

difficult; and I avoid shelling out $250-$300.



Anybody see a flaw in this reasoning?

As long as you are never drwing 30 amps from the generator the cord

will be "adequate". If I was setting up fresh I would buy a heavier

cord - but what you have will continue to do the job.

Again, I don't see how you could ever draw 30 amps from a 4KW generator
on any one conductor. AFAIK, you can only do half of that.

On Sunday, July 27, 2014 4:02:53 PM UTC-4, trader_4 wrote:
On Sunday, July 27, 2014 3:25:32 PM UTC-4, wrote:

On Sun, 27 Jul 2014 13:01:27 -0400, "Ralph Mowery"



wrote:











"trader_4" wrote in message



...







Maybe I'm wrong, but I don't think you can do 30 amps. You have two



identical generators that together put out 4KW. I may be wrong, but I'm



betting that a generator that's rated at 4KW can only do that 4KW with



a balanced load, ie either 16A @ 240V or 16A on each leg supplying 120V.



In either case it's not thg 32A that you're anticipating. To do that



it would have to be supplying 32A at 120V all to one leg and I don't think



it does that, is rated to do it etc. So, I think the voltage drop is



actually half what you think it is. And even if it wasn't I'd still be



OK with the 10g.







That is EXACTLY what paralleled inverter generators do. They parallel



synch and put out double the output of one generator into a single 120



volt line - unless they are connected "series synch" which gives you a



220/120 center tapped output which puts 15 amps max on each "leg".





I don't see why paralled generators would be paralled into just

one 120V line. Seems more logical to just parallel both legs. If you

can parallel one, why can't you parallel both legs? And regardless,

it doesn't change what I posted about his voltage drop issue, ie

the amperage on the conductors being 16A max, which is half of what he

thinks it is.

I just looked at the specs of the Honda EU200i which I think is the
unit he actually has. It's strictly 120V, no 240V and it's rated at 13
amps continous. So there are not two legs involved like you;d have
with a generator that's 240/120V and if you parallel two of them, you'd
get 26 amps on the conductors.

So, I agree with Pete's analysis of the current and voltage drop.
As I said, I'd be OK with it and use 10g cable. Especially if he already
has it.

wrote in message
...
These "motor geerator sets" were "ward leonard" drives - AC motor
running DC generator to run variable speed DC motors bu varying the
field current of the DC generator. Parallelling DC generators is not a
serious problem Parralleling AC generators is a lot of fun, unless one
of them is a synchronous generator (like an overdriven induction
motor)

The MG sets we were using were 3 phase 480 volt systems. We often used the
light bulb or voltmeter system to put them in parallel. When the bulbs went
out or the volt metes went to 0, then the switch was flipped. They then
drove a bank of about 16 motors that were around 3 or 5 HP at 480 volt, 3
phase.

"Rick" wrote in message
b.com...
On 07/27/2014 03:29 PM, wrote:

The inverters "link" - the pwm signal from the one inverter bank
drives the other bank as well. It is more than just the outputs
connected. In the one's I've seen the second unit (partner) is
switched to the "partner" mode instead of the "stand-alone" mode and
it picks up the synch signal from the output of the "master" to run
the inverter on the "partner". Basically the "smarts " of the partner
unit are shut off and it gets the timing signal from the master.


Would that make it single-phase 240 or two-phase 240?

We don't even need to get that started again. It would be whatever one of
the generators put out.
Call it whatever you want.

"trader_4" wrote in message
...
I just looked at the specs of the Honda EU200i which I think is the
unit he actually has. It's strictly 120V, no 240V and it's rated at 13
amps continous. So there are not two legs involved like you;d have
with a generator that's 240/120V and if you parallel two of them, you'd
get 26 amps on the conductors.

So, I agree with Pete's analysis of the current and voltage drop.
As I said, I'd be OK with it and use 10g cable. Especially if he already
has it.

I guess that we jumped the gun and assumed it was a 120/240 volt unit
instead of a single 120 volt unit. So that would be correct that he could
get 26 amps at 120 volts. Even at that the # 10 wire should be large enough
, especially as it is already installed.

On Sun, 27 Jul 2014 14:40:02 -0500, "Terry Coombs"
wrote:


Parallelling DC generators is not a
serious problem Parralleling AC generators is a lot of fun, unless one
of them is a synchronous generator (like an overdriven induction
motor)

https://en.wikipedia.org/wiki/Synchr...ing_current%29
Hey, I didn't say it was impossible - but not something the average
homeowner is going to want to have to do every time there is a power
outage.

On Sun, 27 Jul 2014 15:59:25 -0400, Rick
wrote:

On 07/27/2014 03:29 PM, wrote:

The inverters "link" - the pwm signal from the one inverter bank
drives the other bank as well. It is more than just the outputs
connected. In the one's I've seen the second unit (partner) is
switched to the "partner" mode instead of the "stand-alone" mode and
it picks up the synch signal from the output of the "master" to run
the inverter on the "partner". Basically the "smarts " of the partner
unit are shut off and it gets the timing signal from the master.


Would that make it single-phase 240 or two-phase 240?
It would give you exactly what you get on a typical north american
power line. Center tapped single phase 240. You won't get me into any
arguement/discussion of whether it is single or 2 phase.

On Sun, 27 Jul 2014 16:44:52 -0400, "Ralph Mowery"
wrote:


wrote in message
.. .
These "motor geerator sets" were "ward leonard" drives - AC motor
running DC generator to run variable speed DC motors bu varying the
field current of the DC generator. Parallelling DC generators is not a
serious problem Parralleling AC generators is a lot of fun, unless one
of them is a synchronous generator (like an overdriven induction
motor)

The MG sets we were using were 3 phase 480 volt systems. We often used the
light bulb or voltmeter system to put them in parallel. When the bulbs went
out or the volt metes went to 0, then the switch was flipped. They then
drove a bank of about 16 motors that were around 3 or 5 HP at 480 volt, 3
phase.

OK, so basically mechanical phase converters?
The input was single phase AC? How did you vary the speed of the prime
mover?Mechanical variable speed drive?

wrote:
On Sun, 27 Jul 2014 14:40:02 -0500, "Terry Coombs"
wrote:


Parallelling DC generators is not a
serious problem Parralleling AC generators is a lot of fun, unless
one of them is a synchronous generator (like an overdriven induction
motor)

https://en.wikipedia.org/wiki/Synchr...ing_current%29
Hey, I didn't say it was impossible - but not something the average
homeowner is going to want to have to do every time there is a power
outage.

Well , there is that ...

--
Snag

wrote in message
...
The MG sets we were using were 3 phase 480 volt systems. We often used
the
light bulb or voltmeter system to put them in parallel. When the bulbs
went
out or the volt metes went to 0, then the switch was flipped. They then
drove a bank of about 16 motors that were around 3 or 5 HP at 480 volt, 3
phase.

OK, so basically mechanical phase converters?
The input was single phase AC? How did you vary the speed of the prime
mover?Mechanical variable speed drive?

I did not get into the prime mover that much, but I think it was a DC
electronic drive that powered the motor part. The main power fed to the
varitable speed part was 60 Hz 480 volt 3 phase. I think it was converted
to DC to drive the motor part that controls the speed and then to the
generator part that puts out lower frequency ( probably lower voltage also)
3 phase AC. I know it had a knob on it so we could change the speed of the
motor driving the AC generator. When I needed to put one on line, I hooked
a box up to some plugs on the speed control drive and adjusted the speed so
the bulbs went out and threw a switch. I was not too concerned about the
actual speed control part as others repaired that. My part of that job was
just to get the MG sets on and off line without causing prblems. My main
job was instrumentation, but had to know a little about most everything so I
could fill in for the electrician that worked on each shift when they went
on vacation.

We also had a newer part of the plant that did the same thing except it was
with all electronic controls and no MG sets. We had a box with meters on it
that we used to sync the inverters to put the spare on and off line when we
worked on the main speed control inverter.

This setup was at a plant that made polyester. The 'small' motors powered
gear pumps that forced the melted plastic out of a die. This speed had to
be constant so the plastic comming out of the die would be the same
thickness. There were 16 small motors being driven at the same time. We
could shut off one or two of the small motors and not cause much of a
problem,but if the whole thing shut off very long (much over 2 minuits) it
would cause a major problem and loss of production. That is why we had a
spare MG set for about 20 of the other MG sets.

On 07/27/2014 02:59 PM, Rick wrote:

[snipp]


Would that make it single-phase 240 or two-phase 240?

"two-phase 240" sounds like you'd get 480 across the whole thing.

These things are relative to ground, so it's a matter of what you do
with the point that's between the generators.