holesawing new "knockouts"

[ralph day]

Hi
I'm installing an MNTCB connector/disconnect for my Bergey XL1 and Classic controller.  The wire from the turbine now terminates at a 60 amp disconnect (to be removed), but there's no knockouts on the top of the MNTCB box that will occupy the same space on the wall.  Can I just holesaw the top where appropriate and use the necessary box connector to secure the wire?  It's an all indoor install, so water infiltration is not a worry as it would be in an outdoor app.

Thanks all

Ralph

[Mtn Don]

I have "holesawed" enclosures that did not have enough knockouts or a knockout where it was more convenient for the wiring. Strictly speaking the result may not pass NEC.  However, my new holes were never questioned. One was outdoors but made on the panel case bottom. The inspector passed everything, although it is doubtful he knew there had been a couple extra holes drilled. 

[Robin]

Go for it.

[ralph day]

Done!  Now need to connect, install turbine and reap the benefits.  Mind you, the temp is going to be highs of -7deg C (10 -15deg F).  Freeze to the pole weather!  All in good time.

Ralph

[TomW]

Yeah, we had our main electric entrance replaced a year ago. The licensed and bonded electrician "customized" it by drilling new holes with a step bit to fit the rather unusual location.

I am sure he would not do stuff that was not acceptable.

Just from here.

Tom.

[ralph day]

Disconnect all done.  Now a question about installing and commissioning the turbine and controller.

The turbine is not on the tower yet, but the disconnect and Classic are wired up.  Can I energize the controller (ie turn everyting on) without the turbine attached?  It would be like a non-windy day IMO.  I'd like to have a little time to walk through the Classic  before needing to.

Thanks
Ralph

[TomW]

Disconnect all done.  Now a question about installing and commissioning the turbine and controller.

The turbine is not on the tower yet, but the disconnect and Classic are wired up.  Can I energize the controller (ie turn everyting on) without the turbine attached?  It would be like a non-windy day IMO.  I'd like to have a little time to walk through the Classic  before needing to.

Thanks
Ralph

No problem with that. No different than powered up with no wind (or sun). I have upgraded  a Classic using a 9 volt battery at a friends house who uses Windows. More than once.

DO NOT short the input or damage may be inflicted on the Classic.

Tom

[ralph day]

Thanks Tom and all.

I take it you mean to not have the turbine "braked" (leads shorted).  I gathered that was a no no by the presence of the sticky label by the breakers in the disconnect box saying to be sure it is not "on".

Up here a Clipper is $1600, so my dump loading will be run via relays and use the inverter as a power source for some electric heat.

Ralph

[dgd]

Up here a Clipper is $1600, so my dump loading will be run via relays and use the inverter as a power source for some electric heat.

Ok, so how do you plan the dump loading will operate?  What controls the relays and what do they switch?  I assume they divert the 3 phase AC from the turbine to an inverter in some way.

Dgd

[Robin]

It is not obvious how clippers work. They are not simple! Many classics have been destroyed by home made clippers, so be warned and ask a lot of questions before applying power. We will try to help you with advice , but if you make  bad assumptions and it burns up you will not be covered by warranty. Overvoltage is detected by the classic and stored in non volatile ram. I feel for you and the high price of the clipper, but I have heard this story many times. People seem to get pretty grumpy when their classics go up in flames, so please ask questions. We will try to help you save money, but remember that the final responsibility rests on you.
No I am not trying to scare you into buying our clipper. I would probably do the same in your shoes. I have just seen many home brew clippers not work. You mentioned the word relay.......that raises a big red flag already. I don't get on the forum much, but there are others much smarter than I that will be glad to critique your design before you spend money on it.
Good luck.

[ralph day]

Thanks for you look see Robin.  How often do the designers and builders look at what their end users are doing with their products?  Not GM at least

My system contains:  2.1kw pv.  Bergey XL1. Outback MX60.  Surrette CS batteries.  Midnite Classic 250 and disconnect.  Xantrex 4048 inverter (you see Robin and boB's fingerprints over most of my stuff)

I found the dump loading of my old Southwest windpower controller for the H80 turbine to be too slow, the battery voltage would zing all over the place in high winds with full battery soc.  I used the diversion aux facility of the MX60 to drive an Omron G3NA-240B relay.  The relay switched inverter/house power to a standard outlet which would have an electric heater plugged into it.  Diversion setpoint reached...heater on.  Fast and quiet.  I plan on doing the same with the diversion aux on the MC250...maybe 2 of them.  One for everyday diversion, one for any really high voltage events.  Not sure yet on the number.

I've got planned and sourced the following:  Omron relays, 120volt 1500 watt baseboard heaters (Cadet or Oulette), dc toggle switch to enable aux power to relay control.

I won't be playing with the 3phase ac or the high voltage dc before the Classic...as Robin says it is just too unknown, and the wheel has already been invented and developed with the Clippers.  Just using the house system (inverter ac power) to consume power and keep the Bergey turbine loaded.  Bergey folks have assured me that a freewheeling turbine will not self destruct, but it would be noisy.  A loaded turbine is a happy turbine.

The aux diversion on the MX60 has convinced me that this is the way to go.  With multiple redundancies I should be all right.  In the case of a catastrophic failure of the inverter resulting in no dump available, the turbine will not self destruct (in a not so perfect world that is).

Who knows, a Clipper might be in the future, but I kinda like the simplistic complexity of what has worked for me so far.

Ralph

[bcroe]

Yeah, we had our main electric entrance replaced a year ago. The licensed and bonded electrician
"customized" it by drilling new holes with a step bit to fit the rather unusual location.

I am sure he would not do stuff that was not acceptable.   Just from here.     Tom. 

I much prefer a "Greenlee" punch or equivalent, to a rotating cutter.  Bruce Roe