Re: [RE-wrenches] Enphase AC coupled through autotransformer

The output of a 120/240 volt auto transformer shares neutral with the input when you use to couple a 120 volt device to a 120/240 volt split phase system... there is no isolation because the neutrals are the same connection. I've done AC coupling with auto transformer specifically between

Re: [RE-wrenches] QO Breakers ok for Back feeding?

As I understand it, backfed referred to the source of energization. Current flow alternates both ways at line frequency regardless of the direction of power flow. The reason for marking line and load is because the source of energization remains powered when the device is turned off. In the

Re: [RE-wrenches] LiFePo4

One of the projects I've been working on is a secondary LiIon battery pack solution using refurbished EV battery modules originally build by AC Propulsion and now needing a home. 100Ah or 200Ah x 48 volt nominal. The batteries were originally built for EV use with relatively high performance, so

Re: [RE-wrenches] Max AC coupling backfeed?

I've successfully operated isolated temporary installations where the ac-coupled inverter output significantly exceeds the battery-backup inverter nameplate rating. Obviously there has to be enough firm AC load to absorb at least the portion of the AC coupled output that exceeds the grid tie

Re: [RE-wrenches] 2014 NEC

Code insanity. There is never voltage on the load side of an open AC switch, arc fault, or circuit breaker device supplying a solar inverter that meets UL1741. Solar inverters are current sources only, and only while utility voltage is present. /wk William Korthof 714.875.3576 Sustainable

Re: [RE-wrenches] high efficiency modules in U.S.

/wk William Korthof 714.875.3576 Sustainable Solutions #956904 On Apr 25, 2014, at 7:59 AM, Jason Szumlanski ja...@fafcosolar.com wrote: I heard Canadian Solar prices are on the rise, and supply will be tight and uncertain. Korean made panels were recommended as an alternative.​ Jason

Re: [RE-wrenches] Flashing vs Sealant... again

as a permanent seal) seem like the real factors, not flashings. On flat roofs, issues with drains clogging and ponding are the issues I've seen. Although I would count among the installers to use flashing, I accept the arguments from the proponents of no-flashing installation. /wk William

Re: [RE-wrenches] Busbar 120% rule

service can easily and safely be served by 150A or 175A of utility supply. /wk William Korthof 714.875.3576 Sustainable Solutions #956904 On Apr 3, 2014, at 9:18 AM, Phil Forest pfor...@southmountain.com wrote: Troy, This is my first post. We install 32 amp rated output inverters, reduce

Re: [RE-wrenches] Oddball pumping question

/wk William Korthof 714.875.3576 Sustainable Solutions #956904 On Mar 27, 2014, at 7:19 AM, Chris Mason cometenergysyst...@gmail.com wrote: I have a couple of suggestions. A pump motor of that size is likely Class H and requires a 7x starting current or Locked Rotor Amperage. During starting

Re: [RE-wrenches] NEC 690.10(C) talking points

I think I'm missing something; 690.10 is part of the solar article. A 240 volt welder outlet (utility outlet, usually NEMA #6-50) isn't pertinent to solar, and is allowed anywhere as far as i know, indoors or out. Well, maybe not above the bathtub... /wk William Korthof 714.875.3576

Re: [RE-wrenches] conductors and the 120% rule

(3 phase inverter) or non-additive if you have a bank of 1 phase line/neutral (120 or 277 volt) inverters /wk William Korthof 714.875.3576 Sustainable Solutions #956904 On Mar 4, 2014, at 1:31 PM, Allen Frishman amfr...@aeonsolar.com wrote: what inverter(s) are you using?In many cases

Re: [RE-wrenches] Spacing between ground mounted sub-arrays at 48.5 degrees N latitude

). Each rack also slopes about ~17 degrees from the back legs to the front legs. Net slope of the array is effectively turned near more south than the slope, while still optimizing for a small array footprint. /wk William Korthof 714.875.3576 Sustainable Solutions #956904 On Feb 16, 2014, at 1:35

[RE-wrenches] California State Fire Marshal's Solar Photovoltaic Installation Guidelines

code rules. /wk William Korthof 714.875.3576 Sustainable Solutions #956904 On Feb 14, 2014, at 2:27 PM, Dan Fink danbo...@gmail.com wrote: Hi Bill; That was tongue in cheek about watching my back! But wow I've seen the discussion get heated, even in face to face outreach sessions

Re: [RE-wrenches] schenider Re: morning star ts-mppt-60-600

I've installed a few and they are working great. No issues or problems to report. /wk William Korthof 714.875.3576 Sustainable Solutions #956904 On Feb 12, 2014, at 3:35 PM, toddc...@finestplanet.com wrote: on a related question, do wrenches have any reviews about the schneider/xantrex 80

Re: [RE-wrenches] 208 V 240 in residential applications

. Even electric water heaters and most AC compressors that I've checked also seem to be dual rated (208/240V). Electric car chargers are also agnostic. /wk William Korthof 714.875.3576 Sustainable Solutions #956904 I feel sort of stupid asking this, but it has never come up for me before

[RE-wrenches] Solar Module fire ratings

? Are there any class B or A rated modules on the market? Who's brilliant idea was this? /wk -- William Korthof http://www.sustainsp.com/images/SSP_Logo_RGB_email.jpg 714.875.3576 and 800.524.2970 Sustainable Solutions Partners (also dba: EE Solar) ___ List

[RE-wrenches] Solar-direct pool pumping

experimental beta-test. I remember the SunCentric from several years ago, but not sure how durable that turned out, and I was having trouble a vendor for it now. Any suggestions for today with some favorable track record? Or suggestions on what to avoid? William Korthof Sustainable Solutions Partners

[RE-wrenches] Connecting Two Grid-Battery Backup Inverters to 120/208

and neutral, and xfmr losses... Alternate option is to get an isolation transformer with 208 primary and 120/240 secondary. Bond the midpoint. Better phase balance, but xfmr losses. /wk William Korthof 714.875.3576 Sustainable Solutions #956904 - From: Christopher Warfel We

[RE-wrenches] Solar tariffs

I haven't seen much discussion about the tariffs, but I think the current plan is really an outrage. I've toured the SolarWorld factory twice and used many of their modules---I'd like to see US Solar manufacturers succeed, but I've also toured Chinese factories, and I'm thoroughly impressed by how

Re: [RE-wrenches] RE-wrenches Digest, Vol 5, Issue 113

Interesting update I've installed dozens of non-isolated transformerless inverters with LADWP customers since those genius inverters first became available from Power-One's inverter ancestor, Magnetek. I don't remember ever having a conflict or technical issue with an engineer or inspector

Re: [RE-wrenches] RE-wrenches Digest, Vol 4, Issue 320

Peter, Consider getting a used electric forklift. Every forklift inside a Costco, Home Depot, or Lowe's is electric. I bought a Crown made in the early '90s about 6 years ago and it has always worked tirelessly. The distributor was LA Lift; they supplied a compatible industrial charger and

Re: [RE-wrenches] RE-wrenches Digest, Vol 3, Issue 600

The batteries in my forklift are from the early 90's and continue to perform, despite regular abuse and irregular care. I'll second the comment about the economy of golf cart batteries... They are great for situations where they can be made to fit. They've worked well for me in all sorts of

Re: [RE-wrenches] RE-wrenches Digest, Vol 3, Issue 448

Flashed footings... Cost shouldn't be the problem. You can buy solar stand-offs for around $5 each from Ezee manufacturing (North Hollywood, CA) and Otay rubber flashings for under $5 each. In SoCal, they appear to work adequately for PV mounts and service risers (7-10+ years, no sign of

[RE-wrenches] Heat pump water heater

Does anyone have experience with heat pump water heaters? There are a couple units available now and they seem great---I just purchased one from Lowes (GE hybrid water heater), which has a 700 watt heat pump and 2 standard 4500 watt heating elements... the brains of the water heater let you

Re: [RE-wrenches] Solar System Certification

Yes, Yorba Linda technically requires an electrical PE stamp on PV projects. We've probably done a dozen installations in the city, though I don't think they've enforced the electrical PE requirement on all projects. They do require structural PE on all projects as well, and that

[RE-wrenches] SW 4024 now grid tie

We have three of the Xantrex/Trace GTI units, with one still-in-the- box-new from applications that got modified. They're collecting dust on the shelf... I'd be more than happy to send them to a new home and free up space. William Korthof Energy Efficiency Solar/ Acro (714) 875-3576 1

Re: [RE-wrenches] Shade Mitigating DC Device Application (Matt Lafferty)

Why bother with the DC converters if you only have 2 strings? Get a wide-range, dual-channel inverter (Power One 5000) and plug in the modules however you like. The bypass diodes in the modules will bypass the shaded module sections as appropriate for the conditions, and rest of the modules

Re: [RE-wrenches] RE-wrenches Digest, Vol 2, Issue 944

If the angle differs by more than a few degrees, there will be significant mismatch losses in a single string situation two parallel strings of equal size but different orientations (Fronius white paper) present a much smaller issue. If the angle of modules in a single string varies

[RE-wrenches] utility line voltage issues

I'm beginning to wonder if the allowed voltage range for grid-tie inverters (+/-10%) is too sensitive in some networks and contributes more harm than benefit. This is close to home. We actually have a significant number of customers who've had trouble with grid voltage causing their

Re: [RE-wrenches] AC disconnect options (Andrew Truitt)

1. AC disconnect options (Andrew Truitt) We used to use a lot of those pull-out air conditioner disconnects, we liked the low price. The 60 amp version usually works fine for 15 amps or less, but I really don't think it's reliable at anything close to the 60 amp rating. We've had about