MEP-003A with SX460 VR

[derf]

Disclaimer: These are my opinions and I am not a licensed electrician. Please proceed at your own risk.


Want 2nd opinion here. If I wanted to run a SX460 voltage regulator on an MEP-003A I think I could set the jumper on the SX460 to 120V and connect it to 3 and 6 from the gen head. From the pic, it looks like 3 and 6 always see 120V.

The SX460 wiring would be:
1 and 2 jumped or used for voltage adjust potentiometer/rheostat (R1 on gen panel).
4-3 jumped for 120V operation.
7 on the VR to 3 on the gen head
8 on the VR to 6 on the gen head

F1 to the gen head field
F2 to the gen head field

Frequency selection to 60, of course.


Does this all look correct?

VR instruction sheet:
http://www.cumminsgeneratortechnologies.com/www/en/common/pdfs/avr/TD_SX460.GB_04.05_05_GB.pdf

Terminal 6 on the VR is generally not used.

The SX460 has:
Voltage adjust. It adjusts the voltage. A pot/rheostat on terms 1-2 can be used as a fine voltage adjustment.

Stability adjust. I think this controls how fast it corrects. You don't want it constantly correcting but you do want it correcting for load changes.

Low Freq setting. It will cut power if the frequency drops below a set level. This helps protect loads that are frequency sensitive.

 

[derf]

Here's another wiring pic. It shows a fuse, which is a good idea, on the AC input, terminal 8. A 5 amp fuse should do nicely.
Also, it shows a pot/rheostat on terms 1-2. If you don't use the pot/rheostat just put a jumper across 1-2 or it won't work.
I think the pot/rheostat in the gen panel will work, although the drawing states the pot/rheostat should be 1k 2W.

 

[scrapdaddy]

 

[Isaac-1]

Looks good to me, remember to add fuses to it, and you will probably have to make provisions for the MEP field flash circuit (diode, etc) some talk of this issue is going on over on Smokstak now.

Ike

 

[derf]

The SX460 can pick up a gen with something like 4V to start so the field flash may not be necessary unless the gen sits for a very long time or somehow loses its residual magnetism.
OTOH, a field flash circuit should not be hard to add and would make it even more reliable.

 

[derf]

Helpful video:
[media]http://www.youtube.com/watch?v=i-j-1j2gD28[/media]

How a gen works:
If you spin a coil of wire through a magnetic field it will make electricity.
The magnetic field can be either permanent magnet or, as in this case, electromagnet.
Actually in the case of these gens we are spinning a magnet (rotor) inside of stationary coils (stators).
The Field coil uses DC to make the electromagnet.



The Voltage Regulator (VR) reads and uses the AC output of the gen head to regulate the proper amount of DC to the field to make 120V(in this case). If the gen starts putting out less then 120V the VR will increase the DC to the field. If the gen output goes over 120V it will lessen the DC to the field.

The VR regulates generator AC output by varying the DC input to the generator's field.

Frequency is controlled by how fast the generator turns, 1800RPM in this case is desired to produce 60Hz AC.

Phase is determined by the number and relationship of the stator windings.

 

[Munchies]

Ever do this swap?

 

[derf]

Ever do this swap?

Not yet but the 003 is sitting in the trailer in the back yard now and so is in line to be looked at after a couple of cars get rolling.
I don't know if it will need a VR but if it does I have a spare SX460 on the shelf.

 

[frledda]

Did you ever get the SX460 working?

 

[derf]

Works fine on the MEP-016D but I sold the 003 long ago.

MEP-016D with SX-460 Voltage Regulator

Went through the 016D and got rid of non-essential (to me) stuff. Kept the frequency meter, hour meter, and Volt meter. Replaced the VR with a $25 ebay SX-460. Wired for 120V single phase only.

www.steelsoldiers.com