Installation manual

Common sizes are:

 10 Amp

 16 Amp

 20 Amp

 25 Amp

 32 Amp

 40 Amp

 50 Amp

 63 Amp

Common brands that are widely used include: Noark, Schneider and ABB.

6.2. DC Earthing/grounding explained

Earthing (aka grounding) is done to protect against electric shock hazard. It also helps to

protect against equipment damage from lightning-induced voltage surges in the system.

There is much confusion about what earthing means. The words can mean any of 3 things:

1. Earth electrode: Connecting something to an earth rod or buried conductors.

2. Equipment earthing: Connecting all metal exposed parts to protective "earth" wires

that "bond" cases, conduit, hydro bulkhead etc. together (and to earth).

3. System earthing: Connecting one pole of the supply (for example the DC negative) to

the earth wiring. The earthed pole is known as the neutral pole.

6.2.1. Earth electrode or earth rod

Generally only one wire should go to your earth rod (or

rods). If earth wires need to be combined prior to the

earth rod this is done with an earth busbar in a suitable

enclosure.

Simply connecting something to an earth rod will not automatically make it safe unless you

have a "residual current device" to detect small leakages. An earth rod usually has a

relatively high impedance (resistance). Any small fault current in an earth rod is unlikely to

trip a circuit breaker or to blow a fuse, hence alerting the user to the fault. A very low

resistance earth electrode would be needed to ensure safety if things are not hard-wired to

each other using equipment earth wiring as below. Connecting an earth rod in no way

replaces proper bonding of external metallic parts that could give you a shock due to

differences in voltage between them.

6.2.2. Equipment earthing

For the purpose of this manual, earthing of exposed metal (equipment earthing) is always

required, (but follow your local rules). Use protective conductors (called earth wires) to join

all exposed metal objects together. Make sure you establish a good electrical “bond” that

can last the lifetime of the system. Read the equipment instruction manuals to see what is

recommended. Check local regulations for sizes, these will generally be 4mm

green

insulated copper wire. If your battery bank is earthed then a heavy wire is required to make

this connection normally 16-50mm

or larger. Earth wiring must be able to safely carry

heavy fault currents in the event that a live wire touches the case of an item of equipment.

Bonding items to each other protects people and livestock against getting a shock from

touching two items that might accidentally have a dangerous voltage between them. A fault