Very small solar power system for sleepout

Forums › Home Workshop DIY › Very small solar power system for sleepout

1 | 2 | 3

29098 posts

Uber Geek
+1 received by user: 10209

Trusted

Lifetime subscriber

#2003836 27-Apr-2018 23:49

Aredwood:

And don't ever connect power supplies that have active power factor correction to a modified sine wave inverter. In this case, you will destroy the power supply.

Really? Mine have all been perfect on the trash output inverter that I use when vectors fantastic network tries its hardest to drop from a 3 nines network to only 2. Also on the output of my inverter generator which is also very bad compared to a regular AC supply.

Richard rich.ms

gregmcc

2173 posts

Uber Geek
+1 received by user: 836

ID Verified

Trusted

Lifetime subscriber

#2003859 28-Apr-2018 06:40

redfiat:

Hi

I've got a sleep out with no mains connectivity.

I was thinking of using solar power for this.

Most of the solar companies I've talked to have a minimum kit that costs $6000+++

All I want to do is power 6 LED light bulbs, a laptop, a desktop fan and a few other small appliances.

I believe I need something that can supply up to 400W.

Even if I went up to 1kwh system I think I'd have more than enough.

Any recommendations on what I'd need and where I can get it from please?

(i've looked at jaycar/burnsco/supercheap - they all seem to be 12v/24v systems rather than mains 230v supply)

Thanks.

From memory, any solar installation above 240W becomes high risk prescribed electrical work regardless of been connected to mains or not (standalone), this is due to the high DC currents involved and the fire risk and increased shock risk. Best you get your electrician involved who has solar experience.

nickb800

2735 posts

Uber Geek
+1 received by user: 829

Trusted

#2003896 28-Apr-2018 08:30

For $4000, I wonder if your are better running a (say) 48VDC system. Step down power supply in house takes 240VAC to 48VDC, heavy gauge cable takes that to the sleepout, then regulator to 12VDC for lights and plugpacks, and inverter for mains devices.

Avoiding a mains power system means you save on electrician, and no rigourous requirements to bury the cable between house and sleepout - you could clip it to the fence (Chorus style) with or without conduit to save digging.

Electricity consumption wouldn't cost much, and you won't have to replace batteries.

raytaylor

4076 posts

Uber Geek
+1 received by user: 1296

Trusted

#2003914 28-Apr-2018 09:09

Running the batteries at 24V

- Requires a more expensive inverter
- Requires another battery
- May require different LED lights or a 24>12v step down transformer

Basically adds complications but more importantly, cost.

Though I would recommend going to 24V if your wattage / startup wattage would ever exceed 360 watts

Looking at the electricity regulations, as long as your voltage is below 120V DC then you should be okay

But depending upon the distance, just getting an electrician to install a connection could be much cheaper - if you use a 4mm or larger TPS cable, buried inside a duct between the house and sleepout, then it would probably cost
- $20 for a 20amp fuse
- $120 for an RCD
- $200 for a 50m length of 4mm TPS
- $50 for a 20m length of 2.5mm TPS
- $50 for a sub board
- $80 for 5 PDL wall outlets
- $10 for 1 PDL light switch
- $100 for some conduit or capping
- $10 for a couple of live "cables buried below" signs
- $20 for a 10 amp fuse for lights
- $20 for a 20 amp fuse for power outlets
- $800 for a day worth of labour
- $30 for a roll of electrical danger tape to bury at 30cm
- $150 for duct or conduit to bury the TPS at 60cm

======================================

$1660 to $2k

The electrician can then install 3 or 4 wall outlets on the ceiling for you to plug in whatever LED lamps you want to hang or install up there.

Conservative estimate and all you need to do is get out the shovel and dig a trench

Of course it depends how far the sleepout is from the house.

Ray Taylor

There is no place like localhost

Spreadsheet for Comparing Electricity Plans Here

raytaylor

4076 posts

Uber Geek
+1 received by user: 1296

Trusted

#2003918 28-Apr-2018 09:23

Probably a bit unrelated but for those that are interested....

(2)For the purposes of section 79(1)(a) of the Act, the domestic electrical wiring work that an owner of premises may do is work of any type described in subclause (3) on a domestic installation that has a maximum demand at or below—
(a) 80 amperes per phase if single-phase; or
(b) 50 amperes per phase if multi-phase.

(3) The work to which subclause (2) relates is any of the following:
   (a) removing and replacing fuse links:
   (b) connecting and disconnecting fixed-wired appliances:
   (c) relocating existing switches, socket-outlets, and lighting outlets that are supplied with electricity by tough plastic-sheathed cables:
   (d) removing and replacing any of the following kinds of fittings (but only if the work does not involve work on a switchboard):
     (i) switches, socket-outlets, and light fittings:
     (ii) permanent connection units, ceiling roses, cord-grip lampholders, and flexible cords connected to any of them:
     (iii) batten holders:
     (iv) water heater switches:
     (v) thermostats:
     (vi) elements:

   (e) installing, extending, and altering subcircuits (including submains), but only if—
     (i) the person does not enter (whether directly, or by holding any material or equipment, or otherwise) any enclosure where live conductors are likely to be present; and
     (ii) the work is tested and certified in accordance with Part 2 of AS/NZS 3000, before being connected to a power supply, by a person authorised to inspect mains work.

So to summarise, you could do most of the work yourself, except an electrician would be needed to connect the fuse board in the house, and would need to inspect the wiring including the sub-board in the sleepout

I am going to highly recommend you just look at getting an electrician in to do it rather than going solar based on the cost. Even hiring a landscaper or get your electrician to recommend someone to dig the trench and it will still be cheaper.

Ray Taylor

There is no place like localhost

Spreadsheet for Comparing Electricity Plans Here

redfiat

57 posts

Master Geek
+1 received by user: 1

#2003945 28-Apr-2018 10:32

raytaylor:

So to summarise, you could do most of the work yourself, except an electrician would be needed to connect the fuse board in the house, and would need to inspect the wiring including the sub-board in the sleepout

I am going to highly recommend you just look at getting an electrician in to do it rather than going solar based on the cost. Even hiring a landscaper or get your electrician to recommend someone to dig the trench and it will still be cheaper.

Thanks for your comments. :)

I've already run the sub circuits (rough wiring) through the sleep out, installed the sockets and lights.

I've put a distribution board on the wall and have left all the circuit cables hanging near it ready for an electrician to install.

Will also get him to approve/sign off the work I've done.

Looks like a trench will be the way to go as it is only about 15m between garage and sleep out (garage is where our mains enters the property)

Dell

Shop now for Dell laptops and other devices (affiliate link).

gregmcc

2173 posts

Uber Geek
+1 received by user: 836

ID Verified

Trusted

Lifetime subscriber

#2004042 28-Apr-2018 12:24

raytaylor:
Probably a bit unrelated but for those that are interested....

(2)For the purposes of section 79(1)(a) of the Act, the domestic electrical wiring work that an owner of premises may do is work of any type described in subclause (3) on a domestic installation that has a maximum demand at or below—
   (a) 80 amperes per phase if single-phase; or
   (b) 50 amperes per phase if multi-phase.

(3) The work to which subclause (2) relates is any of the following:
   (a) removing and replacing fuse links:
   (b) connecting and disconnecting fixed-wired appliances:
   (c) relocating existing switches, socket-outlets, and lighting outlets that are supplied with electricity by tough plastic-sheathed cables:
   (d) removing and replacing any of the following kinds of fittings (but only if the work does not involve work on a switchboard):
     (i) switches, socket-outlets, and light fittings:
     (ii) permanent connection units, ceiling roses, cord-grip lampholders, and flexible cords connected to any of them:
     (iii) batten holders:
     (iv) water heater switches:
     (v) thermostats:
     (vi) elements:

   (e) installing, extending, and altering subcircuits (including submains), but only if—
     (i) the person does not enter (whether directly, or by holding any material or equipment, or otherwise) any enclosure where live conductors are likely to be present; and
     (ii) the work is tested and certified in accordance with Part 2 of AS/NZS 3000, before being connected to a power supply, by a person authorised to inspect mains work.

So to summarise, you could do most of the work yourself, except an electrician would be needed to connect the fuse board in the house, and would need to inspect the wiring including the sub-board in the sleepout

I am going to highly recommend you just look at getting an electrician in to do it rather than going solar based on the cost. Even hiring a landscaper or get your electrician to recommend someone to dig the trench and it will still be cheaper.

Solar work above 240watts is high risk prescribed electrical work, outside the homeowner exemption. You need an electrician to do all of the work and an inspector to sign off

gregmcc

2173 posts

Uber Geek
+1 received by user: 836

ID Verified

Trusted

Lifetime subscriber

#2004043 28-Apr-2018 12:25

redfiat:
raytaylor:

So to summarise, you could do most of the work yourself, except an electrician would be needed to connect the fuse board in the house, and would need to inspect the wiring including the sub-board in the sleepout

I am going to highly recommend you just look at getting an electrician in to do it rather than going solar based on the cost. Even hiring a landscaper or get your electrician to recommend someone to dig the trench and it will still be cheaper.

Thanks for your comments. :)

I've already run the sub circuits (rough wiring) through the sleep out, installed the sockets and lights.

I've put a distribution board on the wall and have left all the circuit cables hanging near it ready for an electrician to install.

Will also get him to approve/sign off the work I've done.

Looks like a trench will be the way to go as it is only about 15m between garage and sleep out (garage is where our mains enters the property)

Only an inspector can certify a homeowners work, not an electrician

andrewNZ

2487 posts

Uber Geek
+1 received by user: 1461
Inactive user

#2004064 28-Apr-2018 13:25

gregmcc: Solar work above 240watts is high risk prescribed electrical work, outside the homeowner exemption. You need an electrician to do all of the work and an inspector to sign off

Actually, it appears any solar photovoltaic installed on a building becomes high risk prescribed electrical work.
The only exemption I have found is in relation to portable equipment.

I don't agree with this in any way, but it appears if you attach a solar panel from a calculator to a house it has to be inspected.

I believe the electrical regulators need their wings clipped.

raytaylor

4076 posts

Uber Geek
+1 received by user: 1296

Trusted

#2004078 28-Apr-2018 13:49

I always thought that was a myth created by the solar installation industry.

Based on the theory that if you take two panels in series, there is a possibility that the voltage would exceed 120V DC as the power from the panels heads down to the controller.

Can you please refer me to the legislation as i would be keen to find out more specifics?

Ray Taylor

There is no place like localhost

Spreadsheet for Comparing Electricity Plans Here

raytaylor

4076 posts

Uber Geek
+1 received by user: 1296

Trusted

#2004087 28-Apr-2018 14:08

andrewNZ: Actually, it appears any solar photovoltaic installed on a building becomes high risk prescribed electrical work.
The only exemption I have found is in relation to portable equipment.

This is what I have found so far

My interpretation is that to be High Risk Prescribed Electrical Work, it must first be prescribed electrical work.

-BUT-

Electrical Safety Regulations (2010) say

Schedule 1 clause 2 The following work is not prescribed electrical work

Subclause B Extra Low Voltage Supply
(b) work done on installations, fittings, or appliances that—
(i) are intended solely for connection to, or are associated solely with,
electricity supplies not exceeding extra-low voltage; and
(ii) are not in a hazardous area

Legislation and interpretation is fun :-/

Ray Taylor

There is no place like localhost

Spreadsheet for Comparing Electricity Plans Here

Quic Broadband

Move to New Zealand's best fibre broadband service (affiliate link). Free setup code: R587125ERQ6VE. Note that to use Quic Broadband you must be comfortable with configuring your own router.

gregmcc

2173 posts

Uber Geek
+1 received by user: 836

ID Verified

Trusted

Lifetime subscriber

#2004092 28-Apr-2018 14:15

andrewNZ:
gregmcc: Solar work above 240watts is high risk prescribed electrical work, outside the homeowner exemption. You need an electrician to do all of the work and an inspector to sign off

Actually, it appears any solar photovoltaic installed on a building becomes high risk prescribed electrical work.
The only exemption I have found is in relation to portable equipment.

I don't agree with this in any way, but it appears if you attach a solar panel from a calculator to a house it has to be inspected.

I believe the electrical regulators need their wings clipped.

Only greater than 240w and less than 250KW

There are other conditions that apply like high voltage DC solar......

andrewNZ

2487 posts

Uber Geek
+1 received by user: 1461
Inactive user

#2004094 28-Apr-2018 14:17

Definition of high risk work
AS/NZS5033 has this exclusion.

PV arrays in portable equipment of less than 240 W and less than 50 V open circuit voltage
at standard test condition (STC) are not covered by this Standard. PV arrays of greater than
240 kW at STC are not covered by this Standard.

I've been searching all morning and I can't find anything to exclude tiny installs in a house or other building.

andrewNZ

2487 posts

Uber Geek
+1 received by user: 1461
Inactive user

#2004110 28-Apr-2018 14:28

@raytaylor I agree with your interpretation. I failed to read it fully.

I'm sure an inverter affects things depending on how it's used.

gregmcc

2173 posts

Uber Geek
+1 received by user: 836

ID Verified

Trusted

Lifetime subscriber

#2004114 28-Apr-2018 14:35

raytaylor:

andrewNZ: Actually, it appears any solar photovoltaic installed on a building becomes high risk prescribed electrical work.
The only exemption I have found is in relation to portable equipment.

This is what I have found so far

My interpretation is that to be High Risk Prescribed Electrical Work, it must first be prescribed electrical work.

-BUT-

Electrical Safety Regulations (2010) say

Schedule 1 clause 2 The following work is not prescribed electrical work

Subclause B Extra Low Voltage Supply
(b) work done on installations, fittings, or appliances that—
(i) are intended solely for connection to, or are associated solely with,
electricity supplies not exceeding extra-low voltage; and
(ii) are not in a hazardous area

Legislation and interpretation is fun :-/

You are looking at a very specific section of the ESR, the ESR's also quote a whole lot of other standards that must be complied with, amongst those listed is AS/NZS 5033:2012, photovoltaic arrays.

From ESR's

6A Meaning of low-risk, high-risk, and general prescribed electrical work
(1) In these regulations, low-risk prescribed electrical work—
(a) means prescribed electrical work that comprises the maintenance or replacement
of a fitting in an existing installation; and
(b) includes relocation or extension of a conductor to facilitate replacement
of a fitting; but
(c) excludes maintenance that involves the adjustment of protection or gas
monitor settings of mining electrical equipment.

(2) In these regulations, high-risk prescribed electrical work means the prescribed
electrical work (not being low-risk prescribed electrical work) that—
(a) comprises or includes the installation, or adjustment of the settings, of
any of the following:
(i) an extra-low or low voltage installation that does not, or will not,
comply with Part 2 of AS/NZS 3000:
(ii) an installation that operates, or will operate, at high voltage (other
than high voltage discharge lighting, high voltage mobile mining
electrical equipment, and high voltage relocatable mining electrical
equipment):
(iii) a mains parallel generation system in an installation:
(iv) a photovoltaic system in an installation:

(v) an installation that is, or will be, located in a hazardous area other
than an ERZ0 or ERZ1:
(vi) an installation that is, or is intended, for use with electrical medical
devices:
(vii) any fittings (including any neutral earth resistors and earth leakage
circuit breakers) that—
(A) control earth potential rise; and
(B) are not part of any relocatable mining electrical equipment:
(viii) any fittings or appliances that are not part of any relocatable mining
electrical equipment and are used or installed, or to be used or
installed, in an ERZ0 or ERZ1:

Quite clearly defined in the ESR's solar is high risk, this work must be done by an electrician and inspected by an electrical inspector

1 | 2 | 3