Roof top isolators

Roof top isolators

Burnt-out roof top isolators are a major issue in the solar panel industry.

Over several years, rules have changed, making it mandatory to install these on roof top solar installations.

We replace all roof top isolators with Australian approved and CEC standard models.

As per the ruling by the CEC, the standards mentioned below have to be followed.

7.10 PV array DC isolator at array (Not applicable for micro inverter and AC modules systems).

The positive and negative terminal of a solar array or sub-array represents a hazard with a potentially high risk when the output voltage is 120V DC or above.

Note the following requirements for the PV array isolator at array:

• 7.10.1 AS/NZS 5033:2014 Clause 4.4.1.5 makes it mandatory for an isolator to be installed within 3 meters of the array and visible from both locations for LV systems. This is to enable safe disconnection of the array and isolation of the PV array cable.
• 7.10.1.1 Isolators shall not be installed mid string. For example, where one electrical string is split over different roof faces (all faces are at the same orientation) one isolator is required at the point where the PV panel wiring transitions from the PV array to the fixed wiring to the inverter at the array.
• 7.10.2 Isolators shall not be fixed on any portion of the panel.
• 7.10.3 Isolators shall be fixed to the supports by the use of stainless steel screws (or by screws of galvanically similar material) to minimise corrosion.
• 7.10.4 Isolators shall have an IP rating of at least IP 55, (Note: the CEC recommend using isolators rated to IP66).
• 7.10.5 Isolators shall be UV resistant.
• 7.10.6 The recommended method of fixing isolators is by using fixing points that are on the outside of the enclosure to minimise penetrations and water ingress in to the isolator.
• 7.10.7 When internal screws are used, the designated screw locations shall be used. A dangerous situation may occur if a wire becomes loose and makes contact with the fixing screw. This could put the full array voltage on to the mounting structure (see below).
• 7.10.8 All screw cover caps that are supplied with the isolator or junction box shall be installed.
• 7.10.9 All internal mounting holes should be silicone filled.