Decided to fit a 14.4kW electric boiler to replace our old ageing sold
fuel boiler (getting too old to hump hods of coal around the place).
I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion, we cook
by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and immersion
are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion is
heating AND the EV is charging and I put the kettle on and thje misses
does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower then
apparently you can get a flow switch that tells the boiler to shut down
while the shower is running ---- (we dont have an electric shower)

Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold off
the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.
Andy

On 11/10/2018 10:38, Andy Bennet wrote:
Decided to fit a 14.4kW electric boiler to replace our old ageing sold
fuel boiler (getting too old to hump hods of coal around the place).
I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion, we cook
by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and immersion
are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion is
heating AND the EV is charging and I put the kettle on and thje misses
does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower then
apparently you can get a flow switch that tells the boiler to shut down
while the shower is running ---- (we dont have an electric shower)

Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold off
the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.

Here is one we prepared earlier for you:

http://wiki.diyfaq.org.uk/index.php/...tivated_switch




--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 11/10/2018 10:43, John Rumm wrote:
On 11/10/2018 10:38, Andy Bennet wrote:
Decided to fit a 14.4kW electric boiler to replace our old ageing sold
fuel boiler (getting too old to hump hods of coal around the place).
I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion, we
cook by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and
immersion are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion is
heating AND the EV is charging and I put the kettle on and thje misses
does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower then
apparently you can get a flow switch that tells the boiler to shut
down while the shower is running ---- (we dont have an electric shower)

Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold off
the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.

Here is one we prepared earlier for you:

http://wiki.diyfaq.org.uk/index.php/...tivated_switch



Thanks for the suggestion - seen that - was really looking for an
off-the-shelf-solution
Surely I'm not the first person on the planet to have this problem?

Andy Bennet wrote:

a current monitoring relay that detects if the car is charging and I
use relay output to hold off the boiler

No status light on the EV charge point you can tap into?

On 11/10/2018 11:06, Andy Burns wrote:

Andy Bennet wrote:

a current monitoring relay that detects if the car is charging and I
use relay output to hold off the boiler

No status light on the EV charge point you can tap into?

There is, but it gives 'plugged in' status rather than whether its
charging or not. The car has a timer which I set to start charge at the
start of the economy 7 period.

On 11/10/2018 10:47, Andy Bennet wrote:
On 11/10/2018 10:43, John Rumm wrote:
On 11/10/2018 10:38, Andy Bennet wrote:
Decided to fit a 14.4kW electric boiler to replace our old ageing
sold fuel boiler (getting too old to hump hods of coal around the
place). I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion, we
cook by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and
immersion are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion is
heating AND the EV is charging and I put the kettle on and thje
misses does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower then
apparently you can get a flow switch that tells the boiler to shut
down while the shower is running ---- (we dont have an electric shower)

Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold
off the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.

Here is one we prepared earlier for you:

http://wiki.diyfaq.org.uk/index.php/...tivated_switch



Thanks for the suggestion - seen that - was really looking for an
off-the-shelf-solution
Surely I'm not the first person on the planet to have this problem?
Modify one of the "slave power" controls used for PCs

On Thursday, 11 October 2018 10:38:37 UTC+1, Andy Bennet wrote:
Decided to fit a 14.4kW electric boiler to replace our old ageing sold
fuel boiler (getting too old to hump hods of coal around the place).
I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion, we cook
by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and immersion
are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion is
heating AND the EV is charging and I put the kettle on and thje misses
does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower then
apparently you can get a flow switch that tells the boiler to shut down
while the shower is running ---- (we dont have an electric shower)

Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold off
the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.
Andy

A relay/contactor. Rewind the 240v etc coil to give the right number of amp-turns with wire as thick as possible. 5A seems an odd threshold though.


NT

On Thursday, 11 October 2018 10:38:37 UTC+1, Andy Bennet wrote:
Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold off
the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)

You can get shower priority units eg
http://www.meteorelectrical.com/dist...-priority.html

EV as 'no 2' and boiler as 'no 1' so the EV gets continuous charging except when the boiler control is calling for heat.

Owain

On 11/10/2018 15:46, wrote:
On Thursday, 11 October 2018 10:38:37 UTC+1, Andy Bennet wrote:
Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold off
the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)

You can get shower priority units eg
http://www.meteorelectrical.com/dist...-priority.html

EV as 'no 2' and boiler as 'no 1' so the EV gets continuous charging except when the boiler control is calling for heat.

Owain




Thanks for that, almost exactly what I need - with a bit of bodgery I
think it will do the job.

Andy

On 11/10/2018 15:46, wrote:
On Thursday, 11 October 2018 10:38:37 UTC+1, Andy Bennet wrote:
Does anyone knowledgable know if I can get a current monitoring relay
that detects if the car is charging and I use relay output to hold off
the boiler if the car is pulling (say) more than 5A??? (The car
initially charges at 7kW (32A) when eco7 starts.)

You can get shower priority units eg
http://www.meteorelectrical.com/dist...-priority.html

EV as 'no 2' and boiler as 'no 1' so the EV gets continuous charging except when the boiler control is calling for heat.

Owain



Digging around further, I think I only need one of the componets of this
unit, the priority relay.
A quick google finds several DIN mounting types - a lot cheaper than
buying the whole shower controller.
Just put the EV load through the relay, and the clean contacts tell you
if it pulling over 13A or not - absolutly ideal. Didn't know these
things existed!

On 11/10/2018 12:33, wrote:
On 11/10/2018 10:47, Andy Bennet wrote:
On 11/10/2018 10:43, John Rumm wrote:
On 11/10/2018 10:38, Andy Bennet wrote:
Decided to fit a 14.4kW electric boiler to replace our old ageing
sold fuel boiler (getting too old to hump hods of coal around the
place). I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion, we
cook by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and
immersion are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion
is heating AND the EV is charging and I put the kettle on and thje
misses does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower
then apparently you can get a flow switch that tells the boiler to
shut down while the shower is running ---- (we dont have an electric
shower)

Does anyone knowledgable know if I can get a current monitoring
relay that detects if the car is charging and I use relay output to
hold off the boiler if the car is pulling (say) more than 5A??? (The
car initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.

Here is one we prepared earlier for you:

http://wiki.diyfaq.org.uk/index.php/...tivated_switch



Thanks for the suggestion - seen that - was really looking for an
off-the-shelf-solution
Surely I'm not the first person on the planet to have this problem?
Modify one of the "slave power" controls used for PCs

Most of the off the shelf solutions will assume the load you want to
monitor can be fed from a 13A plug. Less useful for high load fixed
radial circuits.


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 11/10/2018 18:13, John Rumm wrote:
On 11/10/2018 12:33, wrote:
On 11/10/2018 10:47, Andy Bennet wrote:
On 11/10/2018 10:43, John Rumm wrote:
On 11/10/2018 10:38, Andy Bennet wrote:
Decided to fit a 14.4kW electric boiler to replace our old ageing
sold fuel boiler (getting too old to hump hods of coal around the
place). I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion, we
cook by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and
immersion are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion
is heating AND the EV is charging and I put the kettle on and thje
misses does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower
then apparently you can get a flow switch that tells the boiler to
shut down while the shower is running ---- (we dont have an
electric shower)

Does anyone knowledgable know if I can get a current monitoring
relay that detects if the car is charging and I use relay output to
hold off the boiler if the car is pulling (say) more than 5A???
(The car initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.

Here is one we prepared earlier for you:

http://wiki.diyfaq.org.uk/index.php/...tivated_switch



Thanks for the suggestion - seen that - was really looking for an
off-the-shelf-solution
Surely I'm not the first person on the planet to have this problem?
Modify one of the "slave power" controls used for PCs

Most of the off the shelf solutions will assume the load you want to
monitor can be fed from a 13A plug. Less useful for high load fixed
radial circuits.


True, but I believe they use the voltage drop across a pair of
back-to-back diodes as the sensing circuit, so these could easily be
beefed-up. The output would drive a contactor. But it seems that a
"priority relay" is the thing - I hadn't heard of them until this thread.

On 11/10/2018 19:59, wrote:
On 11/10/2018 18:13, John Rumm wrote:
On 11/10/2018 12:33, wrote:
On 11/10/2018 10:47, Andy Bennet wrote:
On 11/10/2018 10:43, John Rumm wrote:
On 11/10/2018 10:38, Andy Bennet wrote:
Decided to fit a 14.4kW electric boiler to replace our old ageing
sold fuel boiler (getting too old to hump hods of coal around the
place). I'll add we are off the gas grid.
Yeah I know I could go oil or LPG but prefer electric.
We have an EV (electric vehicle), our DHW is electric immersion,
we cook by electric .... you can see where this is going yet?
Had the supply upgraded to 100A when we got the EV. The EV and
immersion are generally only run overnight on economy 7.
Now, if the heating comes on at 6 in the morning AND the immersion
is heating AND the EV is charging and I put the kettle on and thje
misses does a fryup I think I have an over 100A problem.

The boiler has a shower switch input - if you have a 10kW shower
then apparently you can get a flow switch that tells the boiler to
shut down while the shower is running ---- (we dont have an
electric shower)

Does anyone knowledgable know if I can get a current monitoring
relay that detects if the car is charging and I use relay output
to hold off the boiler if the car is pulling (say) more than 5A???
(The car initially charges at 7kW (32A) when eco7 starts.)
Any helpful suggestions welcome.

Here is one we prepared earlier for you:

http://wiki.diyfaq.org.uk/index.php/...tivated_switch



Thanks for the suggestion - seen that - was really looking for an
off-the-shelf-solution
Surely I'm not the first person on the planet to have this problem?
Modify one of the "slave power" controls used for PCs

Most of the off the shelf solutions will assume the load you want to
monitor can be fed from a 13A plug. Less useful for high load fixed
radial circuits.


True, but I believe they use the voltage drop across a pair of
back-to-back diodes as the sensing circuit, so these could easily be
beefed-up. The output would drive a contactor. But it seems that a
"priority relay" is the thing - I hadn't heard of them until this thread.

Yup, not looked at them before either...

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/