Amptec Electric Flow Boiler Relay Control Alternatives

[Mishto]

Hi All,
First post for me . Am about to replace/install two Amptec C900 electric boilers (from old Amptec to newer Heatrae Sadia versions).
Under the current regs and specs for these boilers it is recommended that two relay units from Heatrae Sadia (RF 1 & RF 2) are used. One to insure pump operation if any one boiler is running and the other due to an electric shower being installed at the same property. Does anyone have any cheaper solutions, installing the proprietary relays from Heatrae which are going to set me back over £250!

I know I need potentially 3 relays (240v, 10A, 2 x Normally Open Contact and 1 x 240v Normally Closed contact - for electric shower) just want to make sure I get good quality stuff.

This is for my girlfriends property so could possibly earn a few extra brownie points if I can get this up and running between Xmas and New Year!

Any pointers, advice, recommendations or abuse welcomed in equal measures.

Many thanks for any help/assistance in advance.

Ps am aware of similar post from 6 years ago, just wanted to keep it current and hopefully more conclusive.

 

[telectrix]

electric shower will be around 40A. a contactor might be more approproiate.

 

[Mishto]

Telectrix. Thanks for your reply. The relay does not switch the high current to the boiler, only the control signals.

 

[the pict]

Just been on a job where the plumber has fitted one of those electric boilers and it is costing a fortune to run, going there tomorrow to fit the relay for a shower and a wireless roomstat, I tried to find a current relay to save running a cable all the way to the shower switch/isolator but gave up , If you are stuck with electric as you only choice be prepared to monitor your Kw usage

 

[Des 56]

Have current sensing(priority) relays been considered ?
The shower/ heating can then be prioritised at the consumer unit

 

[Leesparkykent]

Easy Relay 240V Mains Relay (230V AC 50/60Hz Coil) - Discount Fire Supplies - https://www.discountfiresupplies.co.uk/product/280/558/Easy-Relay-240V-Mains-Relay-(230V-AC-50_60Hz-Coil)

 

[Mishto]

The pict.
Yep, only way to go out here in the sticks. Have looked into alternatives, but with initial outlay of completely new system (either gas or oil) it’s a bit over budget.
Have done a tear down of the Heatrae Sadia RL 1 and RL 2 and their internal components are all available from RS Online and Farnell UK. List price for both units is £270 but if you knock them up yourself have got the price down to £92 for both units, which is a considerable saving for an identical spec bit of kit. Will post pics and links after Chrimbo

 

[davesparks]

£92 for two relays in a box still sounds very expensive to me!

 

[Mishto]

Davesparks. Well it’s 3 relays, plus earth blocks and two IP55 enclosures/din rails etc. Some of the stuff had to be purchased in multiples so that ramped the price up but the point of the post was to replicate two units that were considerably overpriced. If you could expand a bit on details with costings etc that would be enormously helpful. Thanks

 

[davesparks]

Davesparks. Well it’s 3 relays, plus earth blocks and two IP55 enclosures/din rails etc. Some of the stuff had to be purchased in multiples so that ramped the price up but the point of the post was to replicate two units that were considerably overpriced. If you could expand a bit on details with costings etc that would be enormously helpful. Thanks

I can remember exact prices but I’d expect three standard relays with bases, enclosures, cable glands etc to come within £50.
Why do you need IP55?

 

[Mishto]

Cheers for reply davesparks.
Probably over cautious but site of boiler is in cupboard in bathroom with secondary CU running from downstairs. The bathroom gets so wet when (two girls in the family use shower!!) due to condensation. Listed building/inadequate ventilation etc etc no room in current board for jack!! Trying to keep workload to minimum as only have till 2nd January before up north for 3 months and getting supplies is a nightmare down here as most places (Denmans etc) is closed for this period! Hshaha!!

 

[Mishto]

Priced up with alternative relays/sockets/covers (no enclosures/rails etc) and came to £40 but the extra fecking about (larger enclosures due to depth of this particular relay) and time would push it over time limit. It’s the time that I don’t have unfortunately!

 

[davesparks]

Which relays are you using? Relays and bases used for this kind of thing are pretty much standardised to a form factor, and enclosures come complete with din rail and earth terminals.

 

[Mishto]

Parts list for Amptec Relays (RL 1/RL2) alternative build.

2 Way WPE 4 Earth Terminal Block
https://uk.rs-online.com/mobile/p/products/5280217/

Vishay 47nF Polyester Capacitor
https://uk.rs-online.com/mobile/p/polyester-film-capacitors/0118154/

ABS Enclosure
https://uk.rs-online.com/mobile/p/products/4984227/

TE CONNECTIVITY RT78724 Relay Socket
http://uk.farnell.com/te-connectivity/rt78724/socket-din-3-5mm-pitch-screw-term/dp/9913513

SCHRACK - TE CONNECTIVITY RTB14730 General Purpose Relay
http://uk.farnell.com/schrack-te-connectivity/rtb14730/relay-spdt-250vac-12a/dp/1175036

 

[Mishto]

Parts list for Amptec Relays (RL 1/RL2) alternative build.

2 Way WPE 4 Earth Terminal Block
https://uk.rs-online.com/mobile/p/products/5280217/

Vishay 47nF Polyester Capacitor
https://uk.rs-online.com/mobile/p/polyester-film-capacitors/0118154/

ABS Enclosure
https://uk.rs-online.com/mobile/p/products/4984227/

TE CONNECTIVITY RT78724 Relay Socket
http://uk.farnell.com/te-connectivity/rt78724/socket-din-3-5mm-pitch-screw-term/dp/9913513

SCHRACK - TE CONNECTIVITY RTB14730 General Purpose Relay
http://uk.farnell.com/schrack-te-connectivity/rtb14730/relay-spdt-250vac-12a/dp/1175036