This guide is intended for electricians installing PhiSaver.
Equipment
You’ll receive an enclosure with everything required:
- 1x IotaWatt central unit, pre-configured
- ~10x CTs (current transformers, walnut sized with 1.2m lead)
- 1x VTs (voltage transformer, a plug pack)
- 1x USB cable
- (optional) 1x microcomputer (matchbox size), pre- configured.
- (optional) extra 1x USB cable for microcomputer
- (optional) USB adapter (240VAC to 5VDC), or use a GPO with USB outlets.
The final install looks like this:

… and this on the inside:

Step 1 : Powerpoints / GPOs
Install a GPO is necessary. Two points (one VT, one USB power) are required. If necessary, the USB power is a pass-through unit but two points are neater. Install in the board (DIN) or externally. Later, route the two cables (VT, USB) from the plugpacks to the enclosure.
Step 2 : Mount the Enclosure
The enclosure is about 200×300 and waterproof. Mount next to the board. CT cables will pass from the board to the enclosure.
Depending on the wall, it is possible to route the cables inside the wall. Otherwise, use 32mm conduit to pass the cables through.
Step 3 : Install CTs
Clip the active (only) of each monitored circuit with a CT. A list is supplied of which circuits get which CTs. After clipping, route the lead to the IotaWatt. Each CT is numbered and plugs into the IotaWatt.
Step 4 : Install VTs and USB
Plug in the 9v transformer (the heavy one) and route the lead to the IotaWatt. It is labeled “9V AC REF”.
Plug in the USB adapter and cable, and route to the IotaWatt. It is labelled “5V DC USB”
Plug in the second USB cable to the adapter, and route to the red and white microcomputer. Plug it in to the microcomputer as shown below.


Step 5 : Power Up and Check
Turn on power and everything will connect. Wait five minutes. Contact Brett for final checks and instructions.
Checklist:
- The CTs are correctly clipped (should be a ‘click’)
- CT1 is in socket 1, etc.
- The jacks are are fully pushed into the IotaWatt (easy to miss).
- 9V AC transformer is plugged into GPO and IotaWatt.
- IotaWatt: pulsing green light
- Microcomputer (if used): pulsing green light
Safety Note: All CTs must be plugged in to the IotaWatt.