Jump to content

Startling electric usage.

Dr Bradley

By Dr Bradley
in General Boating

 Share

Featured Posts

Dr Bradley Rising Star

Dr Bradley

Posted
Posted

The other week I managed to detroy my bilge pump and disconnect the tube from the stern greaser. The ingress of water got steadily worse and all my attemts to to reconnect the greaser tube failed. I rigged up my shower pump as an emergency bilge pump' By this morning it was going almost contiuously. I have now managed to reconnect the tube after coming up Stockton locks. I reccount this only as explanation of the only chenge that has been made recently.

 

Yesterday I travelled from Warwick to the bottom of Stockton locks. My Smartguage suggests the batteries were up to 84% by the end of the day and only down to 78% by this morning. After a couple of hours travelling up the locks, Smartguage is recordiing 34%. I thought I was putting electric in. Surely a shower pump, even running contiously could not use this amount of electricity - nothing else was on - and a 550A battery bank with new batteries.

 

How can I drain so much electricity whilst travelling.

Link to comment
Share on other sites
Nickhlx Veteran

Nickhlx

Posted
Posted

I've never quite trusted Smartuage.It does give some unbeilavable readings, but not like this.

 

....and you were travelling ? Surely the alternator would have been charging as well then ?

 

Was the immersion heater on ?

 

Nick

Link to comment
Share on other sites
Paul C Veteran II

Paul C

Posted
Posted

Well hopefully there is a plausible explanation why the smartgauge is reading 34% state of charge, when clearly you'd hope a bit more is left in it. Have a look on the smartgauge website, it might be because there's a constant load running which is 'confusing' the readings. Try 5 mins with the shower pump off and see what happens?

Link to comment
Share on other sites
wrigglefingers Experienced

wrigglefingersDonate to Canal World

Posted
Posted

Interestingly, I've been doing some washing.

 

Which isn't remotely interesting in the least except that despite charging at 60+ amps (engine running at 1000rpm) the usage on the Adverc meter clearly stated that -160 amps were being drawn. So my washing machine on the heating cycle was drawing something like 220 amps.

 

I promptly changed the washing cycle to cold run and found it was drawing about 8 amps in total. I'm slightly mystified by this as my cabling is only rated at 30 amps domestic so surely the cable should have melted or burst into flames? I don't think it has - well, it hasn't in the places I can see, so what haven't I understood?

Link to comment
Share on other sites
Nickhlx Veteran

Nickhlx

Posted
Posted (edited)

Interestingly, I've been doing some washing.

 

Which isn't remotely interesting in the least except that despite charging at 60+ amps (engine running at 1000rpm) the usage on the Adverc meter clearly stated that -160 amps were being drawn. So my washing machine on the heating cycle was drawing something like 220 amps.

 

I promptly changed the washing cycle to cold run and found it was drawing about 8 amps in total. I'm slightly mystified by this as my cabling is only rated at 30 amps domestic so surely the cable should have melted or burst into flames? I don't think it has - well, it hasn't in the places I can see, so what haven't I understood?

 

 

 

I think the washing machine would set light to the cabling if it drew 220 amps through 30 amp cable - if it worked at all

so I wonder if your 30 amp cable is carrying mains voltage ?

DC amps is 20 times a.c. amps smile.gif

 

Nick

Edited by Nickhlx
Link to comment
Share on other sites
wrigglefingers Experienced

wrigglefingersDonate to Canal World

Posted
Posted (edited)
I think the washing machine would set light to the cabling if it drew 220 amps through 30 amp cable - if it worked at allso I wonder if your 30 amp cable is carrying mains voltage ?DC amps is 20 times a.c. amps smile.gifNick

 

Ah, now that's really interesting. Thanks to my physics teacher (Mr Tyler - long since electrocuted by his students I suspect) yet another of my long-cherished beliefs has been demolished. He told us DC was 2 x AC amps as it alternates. No wonder I'm so confused about electrickery. I shall go back to regarding it as a black art and stare at the box that is labelled 'not for girls' on Cobbett. The cable to the washing machine is the very large chunky blue stuff. I think it's 30 amp ... wanders off to see if there's a label on the remainder of the reel.PS should the washing machine be drawing 22 amps AC? And should I be using the heating cycle or just put up with dirty clothes?

 

It's 3G2.5mm, BS6500, H05VV

Edited by wrigglefingers
Link to comment
Share on other sites
Alan de Enfield Veteran II

Alan de Enfield

Posted
Posted (edited)

......DC amps is 20 times a.c. amps smile.gif

 

Nick

 

I know you know what you meant but :- Surely an amp is an amp ?

 

You will 'use' less amps for a given 'wattage' on 220v ac compared with 12v dc

 

Amps = Watts / Volts

 

So a 1000 watt load on 220v will draw 4.54 amps, whilst the same load on 12v will draw 83.33r amps

 

If your heater is a 3kw then it will easily be drawing 250 amps off your batteries (via the inverter)

Edited by Alan de Enfield
Link to comment
Share on other sites
Dr Bradley Rising Star

Dr Bradley

Posted
  • Author
Posted

....and you were travelling ? Surely the alternator would have been charging as well then ?

 

Was the immersion heater on ?

 

Nick

 

 

Yes the alterator was charging.Had it on all afternoon once mooored up.

Link to comment
Share on other sites
jonathanA Experienced

jonathanA

Posted
Posted (edited)

Surely an amp is an amp ?

 

You will 'use' less amps for a given 'wattage' on 220v ac compared with 12v dc

 

Amps = Watts / Volts

 

So a 1000 watt load on 220v will draw 4.54 amps, whilst the same load on 12v will draw 83.33r amps

 

If your heater is a 3kw then it will easily be drawing 250 amps off your batteries (via the inverter)

 

its perhpas easier to think of it the other way round

 

Power (amount of work done) in Watts (W) = Volts X Amps

 

so 12v x 220a = 2640W

 

Which is about right for a washing machine heating water. Its also easier to see why at the higher mains voltage (230v) the current (amps) is much less for the same power (wattage).

 

as for the DC amps = 2 x AC amsp or whatever the teacher said well them that can, do and them that can't - teach - thats all I'll say !

 

anyway doesn't help with your problem of why your makeshift bilge pump is using a lot of battery power although if the washing machine was on at the same time all becomes a bit clearer...

Edited by jonathanA
Link to comment
Share on other sites
Paul C Veteran II

Paul C

Posted
Posted

anyway doesn't help with your problem of why your makeshift bilge pump is using a lot of battery power although if the washing machine was on at the same time all becomes a bit clearer...

 

Dr Bradley has a broken bilge pump and makeshift one using shower pump,

 

wrigglefingers is the one running the washing machine.

Link to comment
Share on other sites
wrigglefingers Experienced

wrigglefingersDonate to Canal World

Posted
Posted (edited)

For mains electric? Isn't that a standard size

 

Richard

 

It's' the enormo-fat cable that passes RCD requirements and is twice the size of the cable sold as artic cable at swindlers.

 

I have resolved the the electricity problem by deciding not to stand next to the instrument panel and stare at it intently next time. I shall also turn the music up louder. That solves all the problems in my car.

 

PS the washing machine consumes 34 litres and uses 0.23 kWh for the programme I use. Is that excessive? It's a Miele.

 

DOH !!

 

I stand corrected clearly a 'senior moment'

 

:-)

 

Yes, sorry - I hijecked Colin's thread. Apologies all round.

 

Colin, in the search to find a label on the cable I found my emergency (ie extra) bilge pump - I'm not far from you at Stockton - need a borrow? 

Edited by wrigglefingers
Link to comment
Share on other sites
Nickhlx Veteran

Nickhlx

Posted
Posted (edited)

I know you know what you meant but :- Surely an amp is an amp ?

 

You will 'use' less amps for a given 'wattage' on 220v ac compared with 12v dc

 

Amps = Watts / Volts

 

So a 1000 watt load on 220v will draw 4.54 amps, whilst the same load on 12v will draw 83.33r amps

 

If your heater is a 3kw then it will easily be drawing 250 amps off your batteries (via the inverter)

 

 

 

 

Yes - an amp is an amp

 

It would have been better expressed as ...

 

For a given power ( say 2400 watts) at 240 Volts a.c., (when 10 amps will be the current flowing), if the same power was being drawn on a 12 volt circuit, then the current in this

12 volt circuit would be 20 times larger at 200 amps...

 

( and don't complicate the poor lady with instantaneous peak and RMS powers/currents !! laugh.gif)

 

-------------------------------------------------------------------------------------------------------------------------------------------

 

PS the washing machine consumes 34 litres and uses 0.23 kWh for the programme I use. Is that excessive? It's a Miele.

 

I reckon that is astonishingly good... but then that's what you paid for in a Miele cheers.gif

 

Nick

 

 

Edited by Nickhlx
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.