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Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 11:55 am
by Cols15
Hi everyone,

I've been running this urn as a boiler -

http://www.ebay.com.au/itm/121350302902 ... 1439.l2649

When I plug it into my 15amp gpo it acts as if it's not reviving power, the standby light does not illuminate.

Can something explain why it won't work on this circuit?

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 12:08 pm
by Kimbo
Do other appliances work on that circuit?

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 1:21 pm
by punchy21
:text-imwithstupid:

Is the thermostat bypassed? If not can you hear it clicking when you turn it up and down?

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 1:46 pm
by Matt_Pl
Mate try plugging another device into the 15 Amp gpo.

Esentially the only difference between a 10 amp and a 15 amp Gpo is the larger earth pin and higher CSA of the supply cables. The 15 amp GPO should be run on a single circuit, so double check your circuit breakers/fuse board to make sure they are all on and the fuses are not blown.


Cheers

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 2:02 pm
by Cols15
I have run a variety of appliances in the 15amp gpo with no problems.

I can hear the thermostat clicking in and out when I turn the oh so accurate ebay boiler temperature control.

The boiler seems to have a very simple circuit, it doesn't even have any over temp protection incase the thermostat fails

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 2:26 pm
by 1 2many
Try it on a 10 amp circuit, I am thinking you will have the same problem.

It may actually heat and maybe a failed indicator light. :think:

Failing that can you do a continuity check on the power leads?

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 2:39 pm
by Cols15
I've checked the circuit breaker and it hasn't tripped.

I also had a look at the pins on the boiler plug seeing as the boiler is of the cheaply made variety, compared it to the plug on my pump and the pin sizes/spacing looks to be the same.

I'm interested in finding out why the boiler won't work off this circuit because I'm just about to build a voltage controller, I'm worried that the boiler may not work when run of the voltage controller.

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 2:52 pm
by Cols15
The boiler works as normal off 10amp gpo.

With the thermostat switched to off I get no continuity across any pins,

With the thermostat switched on I get 18.5 ohms across the positive and negative pins only.

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 2:57 pm
by 1 2many
Well thats got me :wtf: '

Are you sure you have power out of the 15 amp gpo. :-B

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 3:17 pm
by Cols15
I have power at the 15amp gpo, it's running my 340lt/min air compressor at this very moment.

I don't know what to look at next?

It's nice to know some others are just as stumped as I am... I thought that all the years of spirit drinking had finally reduced my I.Q down to that of a doorknob.

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 3:22 pm
by 1 2many
Ok try plugging the urn into an extention lead then into your 15 amp socket, it must be a bad connection. :-B

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 3:51 pm
by Matt_Pl
Ok Ive been pondering this all bloody day.

Another option is the pins on a 10 amp male plug are narrower than 15 amp male plugs and the 10 amp plug may simply not be making an good connection with the female inside the GPO., May i suggest that you slightly squeeze together the pins on the ten amp and try again. Another option is replace the 10 amp plug on the urn with a 15 amp plug, or replace the 15 amp GPO with a new one ( if it is old).

A more serious issue could be the electrician who wired the 15 amp plug has switched the neutral and earth but if that was the case you would have died by electric shock as soon as you touched the urn.... :handgestures-thumbdown:

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 5:32 pm
by Cols15
1 2many you were on the money, I Plugged the urn into a lead on the 15amp gpo and it works.

Thank you to everyone for the replies and thank you to Matt_plew and 1 2many for sticking with it and helping me out.


While I have some electrical minded people looking at this thread ide like to ask a question.

If I make a power regulator using this -

http://www.ebay.com.au/itm/181441926669 ... 1439.l2649

Can I cool it with this 240v fan?. I planned on running a switch to turn it on/off independent of the regulator.


http://www.ebay.com.au/itm/290562120154 ... 1439.l2649

I only ask because most of the regulator setups I see on this site are using 12v fans.

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 5:41 pm
by 1 2many
Glad you finaly got it sorted mate, process of elimination sometimes fun sometimes not. :handgestures-thumbupleft:

You could use that fan but it is a bit overkill in size imo and the controller you have pointed out I can only say that I hear they go pop pretty easily.

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 7:41 pm
by Cols15
I thought that fan would be suited as ambient temps can get as high as 45degrees here, not that I particularly want to be running a still in those temps but it's nice to have equipment that would likely do the job if needed.

I purchased 2 of the controllers and will set them both up, if one fails during a run I can switch to the other.

I would have preferred a ssr setup but I have never used them myself, from what I've read they work the same way as automotive relays only the switching is done via led light instead of contact points.
I will probably set one up on the futre.

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 9:09 pm
by 5 o'clock
Cols15 wrote:If I make a power regulator using this -

http://www.ebay.com.au/itm/181441926669 ... 1439.l2649

.


I hope so because others here have and I am having two of them wired up by my sparkie at the moment.

Re: Boiler wont run on 15amp circuit

PostPosted: Mon Jul 14, 2014 9:30 pm
by Yummyrum
Cols15 wrote:I would have preferred a ssr setup but I have never used them myself, from what I've read they work the same way as automotive relays only the switching is done via led light instead of contact points.
I will probably set one up on the futre.



There are two types of SSR , one is isolated like the car relay you are familiar with the other is not.

The SSR VA type is not isolated and is controlled by a potentiometer.Most guys use them around here as they ar cheap and easy.They have a built in controller curcuit. A bit like a high power light dimmer
Negatives are non linear control and need for carful earthing of pot body

The other SSR DA type is isolated ...like a car relay... A infact that is all they are...rhey newd an external curcuit to control them nd is usually controlled by a pulsewidth modulator running at around 1Hz ...but more buggering around but much better IMO .

Re: Boiler wont run on 15amp circuit

PostPosted: Tue Jul 15, 2014 9:03 am
by Cols15
Hi yummyrum

I have see ssr va type controllers as like you said they seem to be common.

Would you be kind enough to explain how a potentiometer can control a relay?. I take it the relay is just not 'open' or 'closed', it must also be the part scrubbing off the unwanted power as its connected to the heat sink?

If you don't feel comfortable answering this question on a forum I understand.
If you feel comfortable sending me a pm please feel free to do that.

Re: Boiler wont run on 15amp circuit

PostPosted: Tue Jul 15, 2014 9:26 pm
by Yummyrum
Cols15 wrote:Hi yummyrum

I have see ssr va type controllers as like you said they seem to be common.

Would you be kind enough to explain how a potentiometer can control a relay?. I take it the relay is just not 'open' or 'closed', it must also be the part scrubbing off the unwanted power as its connected to the heat sink?

If you don't feel comfortable answering this question on a forum I understand.
If you feel comfortable sending me a pm please feel free to do that.


I was intending to do a comprehensive "how it works" on controllers sometime soon but I'll give you a basic run down .

The simple answer is the controllers use a technique called "Phase Control."
The idea behind it to control the amount of power reaching the element by switching on the power at a certain point in each mains cycle .

As our Alternating Current supply is 50 Hz , that means there are 50 cycles every second where the voltage rises from zero to a maximum positive voltage ...then drops back to zero....then rises to a maximum negative voltage ...then drops back to zero ...............There are 100 pulses of power per second ...50 positive and 50 negative . See top pic below

CCF15072014_00001.jpg


So by varying the delay in each cycle before switching on the power ,we can control how much of each half cycle reaches the element ......in the middle diagram the delay is small and most of the cycle is supplied to the element ...in the lower , the delay is much longer so there is very little power supplied .


OK so how do we control the mains cycles when they are happening much faster than we could turn a switch on of off...even faster than a mechanical relay could switch ?

We use a semiconductor device called a TRIAC.
A TRIAC has three terminals ...two switch the main current .....the third is used to trigger the triac into conduction .
Once triggered , a TRIAC will continue to conduct until either the current flowing through it reaches Zero or the supply polarity reverses .
So we trigger the TRIAC at the part of the cycle we want and it supplies power to the element until the end of the cycle ....perfect :handgestures-thumbupleft:


Here is a triac ...the blue thing on the left .
On the right , a basic 300watt light dimmer controller ....guess what ,its a low power version of a SSR VA

Power Controllers.jpg



So whats inside ...basically fuck all ...a few components that delay the mains cycle and produce a trigger current to the TRIAC
The Potentiometer, resistor and capacitor form the delay circuit ,the DIAC breaks down when the voltage across it has reached a certain level and supplies a trigger pulse of current to the TRIAC causing it to conduct until the end of the cycle

CCF15072014_00000.jpg


Hope this helps :D

EDIT : the coil around the pot shaft is part of the interference suppression circuit I omitted to include ....Oh yeah ...and don't use a light dimmer controller to control an element...firstly ,the triac in it can only handle a few amps (hense the 300 watt rating ) and secondly the interferrance suppression coil will get so hot it will melt the plastic shaft off the pot :laughing-rolling: ...I know .... :laughing-rolling: I forgot to remove it when I subrituted the triac for a 40 Amp one :angry-banghead:

Re: Boiler wont run on 15amp circuit

PostPosted: Tue Jul 15, 2014 9:32 pm
by Sinerjee
Is all of that really needed? To be honest I was just going to run a potentiometer if I ever needed to run a voltage controller. More resistance=less voltage.