Does this system look ok?

HappyHippyDad · Apr 25, 2016

I have just finished designing the solar layout for my shed. It's a little different from standard 230V domestic electrics so I was hoping you guys would cast an eye over it and give me some opinions.

I have done all the maths and am happy with the size of the solar panel, battery, inverter and charge controller so it is more the following points I was hoping for some thoughts on:

1. Size and position of the protective devices (fuses and breakers)?
2. Earthing?
3. Types of fuses (blade or inline fuses or something else? Perhaps DC breakers?)
4. Anything else?

Cheers.

HappyHippyDad · May 9, 2016

davesparks said:
Where did you get the inverter?
If they aren't too expensive then I might get one and 'investigate' what's inside

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If you're doing that purely out of interest then fine, but if it's for my benefit at all then you make sure you send me a bill for your time if you do do it as that's very decent.2000W(4000W peak) DC 12V to AC 240v Power Inverter Converter Electronic UK | eBay

Lucien Nunes · May 9, 2016

I just had to repair a little 300W pure sine inverter used to power a piece of kit in the van. The input bypass electrolytic had gone high resistance so it was an easy fix, but I double-checked the isolation arrangement while open. This one has true electrical separation of the output, there is a proper isolation barrier between ELV and LV sides, bridged only by the main DC-DC converter step-up transformer, a small auxiliary transformer to power the electronics on the output side, and a feedback opto-isolator for the DC-DC. The earth contact in the socket is connected to the case, and bypassed to L & N at RF by two Class Y2 10nF caps. Thus, even with the case and/or ELV input earthed, the output can be used as IT. If desired, an N-E link could be made for TN use, with possible minor increase in radiated interference but no electrical issues.

davesparks · May 9, 2016

happyhippydad said:
If you're doing that purely out of interest then fine, but if it's for my benefit at all then you make sure you send me a bill for your time if you do do it as that's very decent.2000W(4000W peak) DC 12V to AC 240v Power Inverter Converter Electronic UK | eBay

It would be for my own interest as much as anything else, plus I have been meaning to put an inverter in the landrover for a long time and never yet got round to it.

Lucien Nunes · May 9, 2016

Over lunch I looked at another, older UK-made quasi sine 400W - this has a solid N-E link, connected to the case, so no IT possible. Also a new cheap 600W in a plastic case (don't blame me, I just found it kicking around) - this has an isolated AC secondary but the earth contact in the socket is solidly connected to DC -ve. As I thought there's quite a selection of arrangements.

Kamikaze · May 9, 2016

happyhippydad said:
I have just finished designing the solar layout for my shed. It's a little different from standard 230V domestic electrics so I was hoping you guys would cast an eye over it and give me some opinions.

I have done all the maths and am happy with the size of the solar panel, battery, inverter and charge controller so it is more the following points I was hoping for some thoughts on:

1. Size and position of the protective devices (fuses and breakers)?
2. Earthing?
3. Types of fuses (blade or inline fuses or something else? Perhaps DC breakers?)
4. Anything else?

Cheers.

View attachment 32080

Have you given the time it will take to charge the battery and how quickly it will discharge under the load of a saw any thought?

HappyHippyDad · May 9, 2016

Kamikaze said:
Have you given the time it will take to charge the battery and how quickly it will discharge under the load of a saw any thought?

Yes, far too much thought! Days and days of it! Maths calculations coming out of my ears! I'm happy with that side of it.

I've now spent the day working out the best tilt of the solar panel based on latitude, season etc etc and had to have a brush up on sin/cos/tan to work out the size/shape of the frame to fit on the east facing shed so that it faces true south, its been quite enjoyable actually.

Kamikaze · May 9, 2016

happyhippydad said:
Yes, far too much thought! Days and days of it! Maths calculations coming out of my ears! I'm happy with that side of it.

I've now spent the day working out the best tilt of the solar panel based on latitude, season etc etc and had to have a brush up on sin/cos/tan to work out the size/shape of the frame to fit on the east facing shed so that it faces true south, its been quite enjoyable actually.

If you discharge the battery below 50% of capacity it will decrease battery life. My reckoning is that you will be lucky to get 12 minutes in every 24 hour cycle.

davesparks · May 9, 2016

Kamikaze said:
If you discharge the battery below 50% of capacity it will decrease battery life. My reckoning is that you will be lucky to get 12 minutes in every 24 hour cycle.

A leisure/deep cycle battery will overcome part of the discharge issue

HappyHippyDad · May 9, 2016

Kamikaze said:
If you discharge the battery below 50% of capacity it will decrease battery life. My reckoning is that you will be lucky to get 12 minutes in every 24 hour cycle.

See post 14 http://www.electriciansforums.co.uk...ical-forum/109935-2000w-inverter-greater.html

I don't need anywhere near12 mins every 24 hour, probably would have had to double or triple the solar panels and battery Ah if I needed that much.

Kamikaze · May 9, 2016

happyhippydad said:
See post 14 http://www.electriciansforums.co.uk...ical-forum/109935-2000w-inverter-greater.html

I don't need anywhere near12 mins every 24 hour, probably would have had to double or triple the solar panels and battery Ah if I needed that much.

Ahhh…it’s all making sense now!