Which board do I have? Current builds use the UL325 main board K1D8388-1CC with the K1D8387-1CC expansion board. Earlier builds use main board K1D8052-1CC with the K1D8080-1CC expansion board. The original K1D7545CC board is no longer available. Read the number on your board before you order — the two generations do not swap one for the other.

Every LA500 takes TWO batteries, not one. Standard builds use two 29-NP712 7AH batteries — or order K74-30762, which is the matched pair pre-wired. XL control box and solar builds use two A12330SGLPK 33AH batteries instead.

Replace them every 3 to 5 years. These operators run off the batteries and use the transformer only to keep them charged, so tired batteries are the single most common cause of an LA500 that runs slowly, stops partway, reverses for no reason, or dies during a power cut. Replacing both at the same age fixes all of those far more often than any board or arm does. Never mix an old battery with a new one — the old one drags the new one down.

Battery choice sets the harness. The 7AH build uses K94-36274-1. The 33AH build needs K94-36596 and the K10-36395 tray. Solar installs use K94-37236.

Which control box do I have? Plastic: K74-36798-1 (LA500), K74-36798-4 (LA500U), K74-39307-1 (LA500UL), K74-34582-1 (LA500CONT). Metal: K74-39309-1 (LA500UL) or K94-36894 with the reset switch already fitted. The older LA500 metal box K74-34696-3 is no longer available.

Which arm do I need? LA500, LA500U and LA500UL take K-LA500UL. The LA500DC takes LA500DC for a single gate, plus LA500DCS as the secondary arm on a dual-gate installation.

This is a 24 VDC operator. The LA400 family is 24 V but a different platform, and the LA412 family is 12 V — neither shares parts with the LA500.