Surge protection Device

[Halfcrazy]

Not at this time. We are recommending a pair of them on 3 phase. I have even had one customer use 3 doubling up the leads 2 per phase after he got hit by lightning. They make great RPM indicators for wind turbines the blue LED's blink in time with the frequency of the turbine at lower speeds it is pretty cool.

[Robin]

You may not like this answer regarding a three phase SPD for wind turbines. A wind turbine is a lightning magnet. Most people think towers are to get the turbine up into the wind so you can watch them twirl around aimlessly. Lightning knows better. They have trained us humans to build these structures so the lightning doesn't have to work so hard to reach earth. Lightning isn't very picky about where it touches down. It likes trees, roofs and especially wind turbine towers. After all we make them out of conductive materials just so the lightning bolts will give preference to the tower over trees and other not so conductive surfaces. Now if you were that little propeller thing sitting on top of the lightning tower, wouldn't you want the best protection you can get? After all, if a direct strike was to happen, that little turbine and all the electronics connected to it are in a world of hurt. I would suggest putting both sections in parallel and using one complete SPD per phase. That gives you 115,000 amps of protection per phase. Give your turbine a reason to thumb its nose at the lightning Gods.

[windpro]

Has anyone had trouble with operation of the MN SPD with the Aurora and Xantrex XW series of inverters on the DC side causing the inverters to go into a ground fault state?   Is the SPD not compatible with transformerless inverters or the Aurora and Xantrex XW built in ground fault protection designs?

[Halfcrazy]

I can officially say the Aurora transformer-less inverter can not use surge protection on the dc side any mov based device will confuse it according to there engineer. We are working with a couple installers to see if removing the LED circuit will allow it to run though. I do not think this is common across the board on transformer-less inverters though?

The XW charge controller seems to be a different issue all together. It will show an active fault on the screen but not blow the fuse. In discussion with Xantrex (Schneider) they claim this to be false they claim there is no fault do to ground fault displayed unless the fuse blows so it sounds like they have an issue in software?

[boB]

I can officially say the Aurora transformer-less inverter can not use surge protection on the dc side any mov based device will confuse it according to there engineer. We are working with a couple installers to see if removing the LED circuit will allow it to run though. I do not think this is common across the board on transformer-less inverters though?

The XW charge controller seems to be a different issue all together. It will show an active fault on the screen but not blow the fuse. In discussion with Xantrex (Schneider) they claim this to be false they claim there is no fault do to ground fault displayed unless the fuse blows so it sounds like they have an issue in software?

Both of these, Aurora and XW charge controller appear to have some kind of ground fault detection bug.  Our SPD draws around 2 milli-Amps on each leg at around 500 to 600 Volts and these inverters/CC's  are not supposed to react until around half (1/2) an Amp of wayward current, so there is some kind of problem with them.

At lower voltages, say, 400 Volts DC, the SPD draws even less current (< 1 mA) and if you clip out the LEDs, even less and may solve this problem but they really need to take a look at how their ground fault works.  At least it sure looks that way to us at the moment.

boB

[Robin]

This is about the fifth question regarding a three phase SPD. We cannot fit 9 TMOVS in our current plastic outdoor case. We presently have 8 and there is really only room for 7.5 when you get up to the 600V units. Things are very tight! We could drop down to 6 TMOVs, but that would leave only two per phase. I wouldn't feel good putting only 2 per phase. That is only 34,000 amps per phase. Sounds like a lot, but previous testing showed you really need three to have a reliable product. We did something a little strange on the power board of the Classic controller. That board is a 4 layer, 4 ounce copper circuit board. There are two holes where the power inductors poke through. We have to fill the holes up until after wave solder otherwise solder may get on the component side of th board during the solder process. We have twist out inserts in these holes. The inserts are actually part of the board that is routed such that you can break out the inner board and discard after soldering. We didn't want to waste that much board space, so we put the circuitry in each of the discardable inserts that are actually a 4 TMOV SPD. Yes, every power board we manufacture also gives us two boards that can be made into a half of our current SPD. We haven't figured out how to hold these small individual boards in position so we can actually run them through the pick and place machines, but we will eventually get to it. We will then need a housing to hold them in. This will all take a lot of work and expense to bring it to market, so for now we are merely saving these small boards. They are all gold plated so they won't corrode while waiting for us to figure out how to use them. Give us some time and we will have single SPD's and possibly a triple too.

[windpro]

I can officially say the Aurora transformer-less inverter can not use surge protection on the dc side any mov based device will confuse it according to there engineer. We are working with a couple installers to see if removing the LED circuit will allow it to run though. I do not think this is common across the board on transformer-less inverters though?

The XW charge controller seems to be a different issue all together. It will show an active fault on the screen but not blow the fuse. In discussion with Xantrex (Schneider) they claim this to be false they claim there is no fault do to ground fault displayed unless the fuse blows so it sounds like they have an issue in software?

Both of these, Aurora and XW charge controller appear to have some kind of ground fault detection bug.  Our SPD draws around 2 milli-Amps on each leg at around 500 to 600 Volts and these inverters/CC's  are not supposed to react until around half (1/2) an Amp of wayward current, so there is some kind of problem with them.

At lower voltages, say, 400 Volts DC, the SPD draws even less current (< 1 mA) and if you clip out the LEDs, even less and may solve this problem but they really need to take a look at how their ground fault works.  At least it sure looks that way to us at the moment.

boB

Did we ever draw any conclusions if clipping the LEDs allowed the SPD to be used for Xantrex XW (and/ or Aurora PVI inverters)? 

I know it is not your job to find issues in other manufacturers products but it sure helps out our industry especially in the state of ground fault electrical codes.  It also helps prevent your products being called incompatible and if so eliminates us installers from purchasing SPDs that cannot be used with certain product lines and looking bad in front of the customer.  Thanks

[Halfcrazy]

Yes Clipping the LED's does fix the problem and after much discussion with some of the inverter engineers we will be redesigning our 600 and 1000 volt SPD's to not reference to ground to fix this.

[mike90045]

Will there be an exchange program for XW owners with original versions ??

[Halfcrazy]

Yes we will work with anyone on transformer-less or XW based units when we get the new boards in. Send an Email with the details of the installation and number of spds etc to Ryan at midnitesolar dot com and I will contact you when we have the new ones ready.