Shelly switches after in/out central heating pump

[McChiel]

Dear experiencers

New with Shelly (since a week or two).
On my Shelly Pro 3, I see that the WiFi drops out very briefly when the central heating pump steps in/out (see attachment)
Tried a lot but don't kno how to solve that?

[thgoebel]

Would propose to attach a snubber (R/C circuit) across L and N of the pump. The pump is driven with one phase only, isn’t it?

[McChiel]

Thank you thgoebel,

Yes it's a one phase only pump.
I'll gues it's the inductive load (pump is already 12 years old)
So maybe time for a new one, AND the snubber as well 😉

 

[terae]

I would not use straight contact through Shelly to 3-phase motor. Not even high load one phase.  Use motor use contactor instead and Pro 1 is enough. Too small contacts to have long lifetime...

[terae]

3 hours ago, McChiel said:

Thank you thgoebel,

Yes it's a one phase only pump.
I'll gues it's the inductive load (pump is already 12 years old)
So maybe time for a new one, AND the snubber as well 😉

 

12 years old is mostly one without any kind of soft-start; it's not only inductive load but high inrush current. It's like switching on short-circuit and will cause always some material loss to relays.

[McChiel]

Hi terae,
Thank you for your reply, the Pro-3 is used for heaters on/off but is not on the drawing.
The pump itself is not switched bij shelly but via a relais. (as you can see in the drawing)

[McChiel]

Just now, terae said:

12 years old is mostly one without any kind of soft-start; it's not only inductive load but high inrush current. It's like switching on short-circuit and will cause always some material loss to relays.

i know.. so i probably going for a new, high sofisticated pump as well

[terae]

3 minutes ago, McChiel said:

i know.. so i probably going for a new, high sofisticated pump as well

It's most wise way when you happen to do modernizing and automation. Less problems, longer lifetime. RC is needed anyway to have no arc happen when switching off.