Sunamp Controller Wiring - EARTHING

[Barney12]

Guys

 

A bit of a post as a "heads up". I was fitting my replacement controllers today (both my Sunamps are being replaced, a story for another day) and nearly forgot to do something pretty fundamentally important. The reason for this post is that I could easily see a busy plumber/sparky/installer completing missing this. 

 

Let me explain firstly with some pictures.

 

Here's the controller as supplied by Sunamp:

 

 

For simplicity I've removed the lid and the earthing fly lead which is screwed to the back panel (you can see the screw just below the contactor bottom right).

 

Then here's the wiring diagram which is on the back of the lid and also printed in the manual:

 

 

So as per the title the thing we need to be focusing on is earthing. You will note that the diagram shows the earthing connection across the three live blocks and then back (assumably to the case?) BUT and it's a BIG but. Look again at the controller image the earth wiring is NOT there. 

 

Nowhere in the manual does it tell you that its your responsibility to make these connections for the earthing. As far as I can see if you were to fail to make these connections the Sunamp unit itself and the controller case would not be earthed. 

 

[ProDave]

A case of the author of the manual not understanding what he is writing about.

 

Those DIN rail earth terminals are not dumb terminals like all the others, they clamp to and make electrical contact to the metal DIN rail which in turn is bolted to the metal back plate.  So to all practical purposes all the earth terminals are already connected together and to the back plate.

 

Adding earth cable fly leads may give you a warm feeling that you have done it right but will make no practical difference

[Barney12]

1 minute ago, ProDave said:

A case of the author of the manual not understanding what he is writing about.

 

Those DIN rail earth terminals are not dumb terminals like all the others, they clamp to and make electrical contact to the metal DIN rail which in turn is bolted to the metal back plate.  So to all practical purposes all the earth terminals are already connected together and to the back plate.

 

Adding earth cable fly leads may give you a warm feeling that you have done it right but will make no practical difference

 

Thats good news but alas another example of the appalling documentation by Sunamp  

[Jeremy Harris]

Yes, I double checked with a meter that all the earth DIN terminals were correctly connected together via the rail on mine, just to be sure all was OK, a bit like checking that all the screws were tight.  Unless you're familiar with DIN rail terminals I'd guess they could make you wonder a bit though.

[Barney12]

17 minutes ago, JSHarris said:

Yes, I double checked with a meter that all the earth DIN terminals were correctly connected together via the rail on mine, just to be sure all was OK, a bit like checking that all the screws were tight.  Unless you're familiar with DIN rail terminals I'd guess they could make you wonder a bit though.

 

Just checked all mine with a meter. Felt safer that way!! 

[Onoff]

Some typical DIN rail terminals:

 

A typical one:

 

 

A blue one:

 

 

A stop end goes on the rail to stop stuff sliding along it:

 

 

And an earth one. As described above, see how the terminals are connected to the rail:

 

 

 

[Barney12]

Every day is a school day  

[Onoff]

You can get copper bus bars to connect terminals together then an end cap for the"last" one.

 

Bits picked at random but you'll get the drift:

 

 

 

Got to redo my CH/HW wiring centre some time so I'll post a pic. Don't wait up!

[Jeremy Harris]

Nice thing abut the internal bus bars is that they make the DIN terminals more stable, too.  The "wobbliness" of some DIN connector blocks, even with tightly clamped end restraints, is a pet hate of mine, especially when trying to tighten up terminal screws.

[Nickfromwales]

I’ve been earthing every single one with fly leads. Just seems sensible to do that from the PoV that any installer that comes behind you won’t then start screaming that you’ve carried out a dangerous install. 

Makes me feel better regardless of functionality tbh. 

Fortifying the earth is no bad thing afaic.