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Posted By Topic: Permanent connected genset, CO & inverter charger

Rhino
Aug 30 2019 16:15

Normal Supply – inverter charger

Alternative supply - Single phase Genset permanently connected to MSB with MEN link

Change over switch – Hager SF263, drawing attached shows generator Neutral switched

ASNZS 3010; 2017 fig 2.4 shows Neutral not switched, 2.7.10.2 (a) suggests it can be switched if the switching of the neutral operates simultaneously with the active conductor.

Seems to be conflicting and suggesting either switched or not switched can be used. I assume fig 2.4 is the correct method. Which to follow?

Also the genset will be connected directly to the inverter chargers AC INPUT, upstream of the CO switch, therefore when the changeover is switched to Genset, the normal supply at the changeover switch (once inverter charger has synchronized and internal relay has closed) will now be feed from the generator supply instead of the inverter. The Normal supply inverter charger neutral will not be switched. Therefore, this would become the generators neutral as well.
Is this going to be a problem?

   

AlecK
Aug 30 2019 17:06

The Figs in "3010" - both currently cited 2005 & yet-2-B-cited 2017 editions
all assume "normal supply is mains.
That's because they are "Typical" diagrams, to illustrate the rules.

If you want to do something a bit different, there may not be a diagram to follow.

You should ALWAYS look at the actual rules. Particularly co for the older edition; because it doesn't even try to illustrate all the rules that usually apply, it only shows the change-over switching.

There's nothing in 2.7.10.2(a) that 'suggests' any switching of genset N. That clause states clearly that for a permanently connected genset the N shall NOT be switched

You should also note that there are several errors in 3010:2017, which are being corrected by an amendment (somehow SA published an earlier version instead of the final version prepared by the Committee). There are several minor errors in Fig 2.4; however the switching shown is correct.

Using an inverter / charger that has common terminals for a.c. input & output is never going to comply; as no charging system , other than a grid-connect inverter (for which there are special rules in place) is allowed to back-feed anything upstream of its point of connection [3000; 7.3.3].

Reference to the unit synchronising makes me suspect you are trying to set up a supplementary supply rather than an alternative supply. Wiring Rules don't cover supplementary supplies other than grid-connect inverters [4777.1].


   

DougP
Aug 30 2019 20:35

The standard drawing with the Hager switch isn't always the correct one.

The instructions are here:
https://www.hagerelectro.com.au/e-catalogue/energy-distribution/control-indication/manual-changeover-switches/changeover-switches/sf263/36396.htm