Overload protection to a central heating pump x2

[Ian1981]

Is it a requirement to provide overload protection to a central heating pump rated at 2.77amps?
I’m kinda under impression that an almost 3 amp pump jamming will get rather hot.
I mentioned this to the heating installer who has requested we just installed 2 x isolators for the pumps through a contactor as to not switch the pumps through the programmer which makes sense.
I am aware that the regulations require that a motor 0.37kw requires overload protection of the motor but a pump is not a motor, at least that’s how I view it.
Thoughts please.

 

[westward10]

Pump is a motor isn't it?

 

[Ian1981]

At the risk of being naive( and incorrect)I thought that the Difference Between a pump and a motor was that a Pump is a mechanical device used to raise or move fluids around using suction or pressure.
A Motor is an electro-mechanical device that converts electrical energy into mechanical energy.

 

[westward10]

What drives the pump, a motor.

 

[LeeH]

The motor drives the pump, how do you think it spins around?

The mechanical energy you speak of is the energy that drives the impeller.

 

[Ian1981]

Overload protection it is.
What do heating engineers know anyhow?

 

[westward10]

At the risk of being naive( and incorrect)I thought that the Difference Between a pump and a motor was that a Pump is a mechanical device used to raise or move fluids around using suction or pressure.
A Motor is an electro-mechanical device that converts electrical energy into mechanical energy.

This is absolutely correct but what drives the mechanical pump, the mechanical energy from the motor.

 

[buzzlightyear]

Overload protection it is.

yes .

What do heating engineers know anyhow

nowt ,that's why they are called wet pants ,there is water coming out of that hole, yeah but which one.

 

[GBDamo]

Pump is a motor isn't it?

certainly has one, unless you're planning on some Heath Robinson affair with strings and elastic bands.

 

[Wilko]

Hi - have you got the pump? Possible that single phase units will have built in overload protection and be plug and play for Mr Plumber.

 

[Ian1981]

Hi - have you got the pump? Possible that single phase units will have built in overload protection and be plug and play for Mr Plumber.

It’s a good idea but I’ve rang grundfos tech and he basically said it’s upto the electrican if he wants to fit overload protection to the pump.
Very helpful he was.

 

[Bobster]

Haven't read the new regs, but in the 17th ed. Any motor under 0.37Kw was exempt from needing overload protection.

 

[Ian1981]

Haven't read the new regs, but in the 17th ed. Any motor under 0.37Kw was exempt from needing overload protection.

Yeah it’s in the 18th
The pump is rated at 2.77 amps high speed setting so it’s required and it’s not incorporated within fixed current using equipment

 

[Bobster]

I'd probably call tech help from the manufacturers first to see why they have omitted it from their controller.

You're going to have to install one to comply if they don't give a valid reason.

 

[Lucien Nunes]

But surely the 0.37kW refers to the motor mechanical output, i.e 1/2 hp in old money. A 0.37kW single-phase 230V induction motor usually takes around 3.5A, so I think your pump motor is less than 0.37kW output and exempt from O/L protection

 

[Ian1981]

This is where ringing the technical department should clarify matters but all I got in response to my question was “it’s upto you as the electrician “
I’ve gone ahead and ordered the overload relay anyway to be on the safe side.
Perhaps not very technical on my part but nevertheless it covers my arse

 

[Ian1981]

This is where ringing the technical department should clarify matters but all I got in response to my question was “it’s upto you as the electrician “
I’ve gone ahead and ordered the overload relay anyway to be on the safe side.
perhaps not a very good technical reason but it covers my arse.
A lack of engineering knowledge of motors on my behalf

 

[johnduffell]

in response to my question was “I've no idea and don't care so cba to find out“

Fixed that for you Ian!
Maybe they put the trainees in tech support and as soon as you appear to know something useful you get moved up to a more responsible job!