Any simple way to wire an MEP-805B to a transfer switch allowing for exercising

[scootertrs]

Any simple way to wire an MEP-805B to a transfer switch allowing for exercising and transferring upon loss of street power and returning to street power once it returns stabilized?

In the alternative, can I convert my mep-805b into a mep-805a. I understand that such a unit allows for a relay controlled exciter/transfer function.

thank you

scootertrs

 

[Guyfang]

This is an extract from TM 9-6115-661-13&P. There are several types of generator set ups, that use a synchronizing circuit, (so called "switch box" below) to allow you to parallel and switch the load from one generator set to another. The rig is simple, and not hard to find. It would allow you to hook up the gen set and street power, parallel both, and change power sources. Your real problem is that the gen set is three phase. Your street power is not. Its still doable, if you find someone smart.

There is no difference between a MEP-805A and MEP-805B, other then the engine.




Power Plant AN/MJQ-39 and AN/MJQ-39A. The AN/MJQ-39 and AN/MJQ-39A Power Plant consists of two
PU-800 Power Units, a power cable and a switch box. The PU-800 Power Units have been identified as either
Unit A or Unit B. The Switch Box is mounted on Unit A and the power cable is stored on Unit B. The electrical
output and towing information are the same as listed for the PU-800 in the Capabilities and Features section in
Table 5 below.

Power Plant AN/MJQ-48. The AN/MJQ-48 Power Plant consists of two PU-801 Power Units, a power cable and
a switch box. The PU-801 Power Units have been identified as either Unit A or Unit B. The Switch Box is mounted
on Unit A and the power cable is stored on Unit B. The electrical output and towing information are the same as
listed for the PU-801 in the Capabilities and Features section in Table 11 below.

Power Plant AN/MJQ-48A and AN/MJQ-48B. The AN/MJQ-48A and AN/MJQ-48B Power Plants consists of two
PU-801A Power Units, a power cable and a switch box. The PU-801A Power Units have been identified as either
Unit A or Unit B. The Switch Box is mounted on Unit A and the power cable is stored on Unit B. The electrical
output and towing information are the same as listed for the PU-801A in the Capabilities and Features section in
Table 11 below.

 

[scootertrs]

Thank you for the reply. I had understood that the 805B unit had a computer-like display and the 805A had a "mechanical or analog gauge display.

As I see it, there are a sequence of steps that are to be followed during start up of the 805B unit which I cannot seem to be able to coordinate with a simple transfer switch that basically just jumpers 2 contacts across 2 terminals when generator power is desired.

As far as 3 phase-single phase power goes, I have come across several conversion methods to make them function as single phase (the generator head being of the twelve wire configuration).

Thus my current sticking point is how do I activate my gen set with my contacts as coming across my transfer switch allowing for exercising and transfer, etc.

In the worst case, I may have to convert my genset into an analog unit if possible to allow it to function as my onan or my katolight generators in other applications.

Thanks again.

 

[DieselAddict]

There is no single phase conversion for the 805. It is a 10 wire head. You can convert a MEP005 but not a MEP805. You are stuck with 3 phase out of that machine.

 

[Guyfang]

This is an extract from TM 9-6115-661-13&P. There are several types of generator set ups, that use a synchronizing circuit, (so called "switch box" below) to allow you to parallel and switch the load from one generator set to another. The rig is simple, and not hard to find. It would allow you to hook up the gen set and street power, parallel both, and change power sources. Your real problem is that the gen set is three phase. Your street power is not. Its still doable, if you find someone smart.

There is no difference between a MEP-805A and MEP-805B, other then the engine.




Power Plant AN/MJQ-39 and AN/MJQ-39A. The AN/MJQ-39 and AN/MJQ-39A Power Plant consists of two
PU-800 Power Units, a power cable and a switch box. The PU-800 Power Units have been identified as either
Unit A or Unit B. The Switch Box is mounted on Unit A and the power cable is stored on Unit B. The electrical
output and towing information are the same as listed for the PU-800 in the Capabilities and Features section in
Table 5 below.

Power Plant AN/MJQ-48. The AN/MJQ-48 Power Plant consists of two PU-801 Power Units, a power cable and
a switch box. The PU-801 Power Units have been identified as either Unit A or Unit B. The Switch Box is mounted
on Unit A and the power cable is stored on Unit B. The electrical output and towing information are the same as
listed for the PU-801 in the Capabilities and Features section in Table 11 below.

Power Plant AN/MJQ-48A and AN/MJQ-48B. The AN/MJQ-48A and AN/MJQ-48B Power Plants consists of two
PU-801A Power Units, a power cable and a switch box. The PU-801A Power Units have been identified as either
Unit A or Unit B. The Switch Box is mounted on Unit A and the power cable is stored on Unit B. The electrical
output and towing information are the same as listed for the PU-801A in the Capabilities and Features section in
Table 11 below.

1. I will correct myself. Yes there is a difference between the 805A and 805B. The 805A has a "normal" control panel. Not touch screen, and there are components in the control panel different. I was thinking of the MEP-804A and 804B models.

2. It would be very difficult to change a 805A to a 805B model. Just a quick look in the parts manuals will, or should convince you of that. They are two different animals. They do not even share the same engine. Not even Macgyver could have much chance of accomplishing that feat.

3. Chris is 1000% correct. You can not convert that gen set.

4. Analog or digital, has nothing to do with your problem. To accomplish what you want to do, you need a way to synchronize your phases. Switching between two different power sources, without interruptions, is NOT possible without synchronizing/paralleling the power sources. I have seen what happens when that doesn't go right. Its not pretty. Now if what you want to do is switch power sources, WITHOUT all this fuss, you simply need a switch that cuts off one power source, and turns on the other. But you WILL have an interruption. Every system plugged into your fire station will lose power, and shut down. Some systems wont make a big deal. Other things sure don't like that. Computers for instance.

5. The for mentioned "Switch Box" allows you to monitor that fact that you have two power sources. It allows you to parallel the power sources. It allows you to move your load, (fire station) from one, to the other power source, without interruption.

 

[scootertrs]

Thanks again. All electronic equipment is 100% backed up and is running off a UPS, thus when the transfer switch starts the genset, warms it up, waits for stabilization then transfers to the genset... it is still running on a 3KW battery powered UPS which will start charging once the transfer happens. AC's and chillers, freezers, etc. will not transfer until power is stable and time lapse (as set per load) expires.

 

[DieselAddict]

You'll need to install an autostart controller on the generator to handle the startup sequence. You should be able to buy one and make it work. Looking at the startup sequence the computer is not required to interact with to start the unit. You just have to let it boot up before starting. This you should be able to do that by programming delays in the autostart controller.

Have you done any research on autostart controllers?

The second thing is the transfer of power. Your ATS should handle that. I suspect it will be configured to do an "OPEN TRANSFER". This means when you transition from generator power back to utility power there will be a 5 second (or so, on some it is configurable) outage. Doing a "CLOSED TRANSFER" is when you can go from generator power to utility power with no blip. This requires a more complicated setup with a phase detector between the generator and the utility. I would be surprised if your setup is equipped with that instrumentation. That greatly complicates the setup of the generator as well. Not to mention a sign off from the power company because there will be some period of time that the utility and generator are parallel with each other. Where I am Duke Power limits this kind of transfer to 100 milliseconds.

Doing a OPEN transfers isn't such a big deal. It just means you'll have a short loss of power when switching between sources.

Its hard to give you any more info without knowing about your entire setup. There is also practical limits on how much we can actually help. You may be well served to contact a local industrial electrician (or electrical engineer) with generator experience or find a generator company to help you sort it all out.

 

[jamawieb]

Here you go for your auto start controller. https://inovahightech.com/store/index.php?route=product/product&path=20&product_id=61
I hope you don't have the 805b because they want $1,999 for the controller and you have to be part of the military to buy it.

 

[scootertrs]

Here you go for your auto start controller. https://inovahightech.com/store/index.php?route=product/product&path=20&product_id=61
I hope you don't have the 805b because they want $1,999 for the controller and you have to be part of the military to buy it.

Wouldn't it be nice if they informed you prior to purchase that you would be limited re parts availability because you are not part of the boys in green? I can corroborate that even if I had the $1999.00 (which I do not) the supplier stated that they could not sell me the autostart part because I was not dressed in od green.

 

[DieselAddict]

That is just crappy right there.

 

[NEIOWA]

Wouldn't it be nice if they informed you prior to purchase that you would be limited re parts availability because you are not part of the boys in green? I can corroborate that even if I had the $1999.00 (which I do not) the supplier stated that they could not sell me the autostart part because I was not dressed in od green.

If you are a public agency (as user of FFP or FEPP surplus to FD) you can purchase parts directly from DLA (and GSA) at their schedule pricing. Contact your state forester to get set up.