This section describes how to properly connect and disconnect solar modules connected to a Tigo Energy maximizer whose combined input power is in excess of 350 watts.
Clause 2.15 in the standard it states, if the input power going into a DC conditioning unit is greater than 350W, an isolator between PV modules and the DC conditioning unit is required to provide safe module disconnection. As stated, as long as each DC conditioning units input power is limited to 350W or less at the time of connection or disconnection, an isolator is not required between the DC conditioning unit and the modules.
Limiting the input power into the DC conditioning unit can be achieved by covering the associated module(s) with an opaque material before breaking the DC input connections, in order to de-energize the circuits.
Labeling the system
For systems where AS/NZS5033:2014, clause 2.15 applies, when installing Tigo Energy DC maximizers (DC conditioning units) with a rated input power greater than 350Wp, a label shall be placed on each DC conditioning, as described below.
Attach the label on the mounting bracket of the maximizer, with the arrow pointing to the DC input connection. If the maximizer bracket is facing the roof, place the label elsewhere on the maximizer where it will be visible.
De-energizing the circuit
When using Tigo maximizers with modules who’s combined input power is greater than 350Wp, to comply with AS/NZS 5033:2.1.5 (c), it is important to perform the following steps prior to any work carried out on the system’s PV Arrays - including handling modules and maximizer connections.
- Turn the inverters AC supply switch to the OFF position.
- If the system has a CCA and mushroom switch, reference the onsite PV OFF safety instructions for site specific instructions. Press the mushroom switch to activate the units PV OFF function, string voltages should be reduced to 0VDC. This can be validated by using an appropriate DC volt meter.
- Use a suitable DC clamp meter to test the current flow within the input circuits of the maximizer to confirm the circuit has been de-energised:
- If current flow is not detected, there is no power in the circuits and the DC inputs are safe to disconnect.
- If current flow is detected (or if a DC clamp meter is unavailable), cover the associated module(s) with an opaque material before breaking the DC input connections, to de-energise the circuits.