Option 1: Tight next to the DB cover or on top of the DB
In this option the electrician will mount the meter tight, next to the DB cover inside the house / flat's DB box. Usually, at existing houses and flats, the electrician use a chasing hammer to make a big enough hole in the wall, right next to the sunked-in DB metal frame to fit the pvc compression gland at the side of the DB's metal frame box.
Some electricians prefer to mount the meter on top of the DB box, therefore making use of the existing sunked in DB metal frame's own pre-drilled holes which is normally closed / sealed with a removable 20mm round metal tab. The chasing hammer still need to be used to make a big enough hole in the wall, right on top of the sunked-in DB metal frame to fit the pvc compression gland. Using a pvc compression gland will ensure that the wiring to and from the meter is insulated and protected.
The hole /channel that you have to chase in the wall must not be longer than 80mm long and will just need to be big enough in width to fit 6 x 10mm / 16mm wires(two sets of life, neutral and earth wires).
The prepaid electricity meter comprises of two components, a wall base and the metering device. The meter's pvc wall base part need to be mounted on top of the hole / channel you made, to cover it up.
Option 2: Mounted back to back
In this option the electrician will drill a 25mm hole right through the DB box's back metal plate with a 25mm holesaw (special metal drill bit). After the pilot hole is made with a 6mm concrete dril bit, a final 25mm hole can be drilled right through the two brick layers with a high impact hilty drilling machine. The meter wall base will be mounted right on top of the hole at the other side of the wall, to cover it up.
In a normal dwelling the main city council supply cable from outside feeds the distribution board inside your house / flat and is directly connected to the main circuit breaker. This main supply cable must be switched off before you re-route the cable. The life, neutral and earth wire need to be ferraled (10mm / 16mm ferrals) through / extended, therefore re-routing the main supply cable to first feed the prepaid meter and then feeding the main distribution board inside your house / flat.
This means that the prepaid meter will still have power, even If the main circuit breaker in the db box inside the house / flat is switched off. Should a customer break our unique meter seals and tamper with the metering device by unplugging the meter device from the wall base unit, the meter will lock in tamper mode, causing the customer to sit without electricity. The picture below illustrate how the wall base unit should be wired.
IMPORTANT: Please make sure that all the power is switched off before you mount the metering device directly onto the wall base unit. The prepaid meter is equipped with a tamper latch to protect revenue. If the meter device is pushed down to fit into the meter base unit while the power is switched on, the meter will lock in tamper mode. When locked in tamper mode, no power will be allowed through the meter, even if there is sufficient money left on the meter.
Should your electrician make this mistake during installation, you just need to contact Global International Meter Services to request a special 20 digit token to unlock your meter. Unfortunately, the issuing of such a request is a manual procedure that is handled by the host centre and this special request could take half a day to be processed. So please, to avoid all this, remember to switched off the power during the installation process.
The figure below shows the basic wiring concept for a single dwelling such as a single house, flat or granny flat. The meter is installed directly after the municipality meter. This ensures that the meter can not be tampered with when the main circuit breaker inside the house or flat is switched off.
The figure below shows the basic wiring concept where multiple dwellings units connected to a single municipal meter are concerned. For example a sectional title scheme or a property with multiple distribution boards serving more than one dwelling unit. The meters are installed before the main circuit breaker in each dwelling unit.