Project background
A factory shutdown gives a panel builder a limited window to connect a new PV cabinet. This Selangor application proposal focuses on preparing the protection circuit before that window arrives. ALP220-EF is assigned to the specified current-protection duty on one feeder, with the CT arrangement and external breaker circuit selected around the approved project design.
What could delay the handover
The relay, CTs and breaker may be ordered from separate specifications. If nobody checks their interfaces together, the panel can reach site with an unsuitable CT input or a trip output that cannot operate the supplied breaker accessory. The installer then has to resolve an equipment mismatch during the shutdown. Clear feeder labels also matter when several cabinets share the switchroom.
A coordinated Acrel protection circuit
Select the ALP220-EF current input to match the specified 1 A or 5 A CT secondary. The relay measures current, indicates protection operation and issues the assigned trip command. Residual-current protection requires the relevant additional configuration and a separate residual-current transformer. Confirm the selected version's system and auxiliary-supply ratings before finalising the order.
The proposed trip path includes the breaker accessory, its operating supply and an interposing relay where the contact duty requires one. The panel builder checks these interfaces on the drawing and tests the complete path before delivery. The test must identify the feeder and confirm the intended breaker's operation; an illuminated relay indicator alone is insufficient.
Expected benefits at installation
Resolving the sensing and trip interfaces in the workshop can reduce avoidable changes during the factory shutdown. A complete functional test gives the EPC evidence that the selected parts operate together. For the factory team, consistent labels and a recorded breaker response make it easier to understand what the cabinet protects and how its trip action was checked.
The handover should contain the approved settings, CT details and functional test record. This proposal addresses the defined feeder current-protection duty; the full grid-interface requirements remain with the approved installation design. Send Acrel the single-line diagram and breaker trip details for a configuration review before the panel order is released.
Post time: Sep-16-2026
