OT80F3 – DISCONNECT

ABB OT80F3 three-pole, front-operated switch-disconnector (non-fusible disconnect switch) for base or DIN-rail mounting, supplied with protected terminal clamps. ABB rates it at 100 A thermal current in the open configuration with AC22A/AC23A operational currents of 80/75 A at 400 V. The operating handle and shaft are ordered separately.

Specifications published by the manufacturer. Source: manufacturer documentation.

Specs

• BrandABB
• TypeSwitch-disconnector (non-fusible disconnect)
• Poles3
• Rated thermal current Ith (open)100 A
• Operational current AC22A/AC23A at 400 V80 A / 75 A
• Cable cross section1.5-35 mm2
• MountingBase and DIN-rail, front operated
• TerminalsProtected terminal clamps, IP20
• Order code1SCA105798R1001

Does code require a disconnect at the outdoor unit?

Yes. NEC 440.14 puts the disconnecting means within sight from and readily accessible from the equipment. Article 100 defines within sight as visible and not more than 50 feet away, so a breaker in a garage panel around the corner does not satisfy it. The 2023 code also pulls in the working space rules of 110.26(A). You cannot mount it where it blocks a service panel or hides the nameplate.

Fusible or non-fusible?

Read the unit nameplate. If it lists a maximum fuse size, or calls for fuse protection, use a fusible pull-out or fused safety switch with the fuses that plate specifies. If the plate allows HACR breaker protection and the branch breaker already provides it, a non-fused pull-out is fine, and that is what most DFW residential splits use. Never fuse above the nameplate maximum to stop a nuisance trip. That number protects the compressor windings, not the wire.

The pull-out looks fine but the unit is dead.

Pull the block and look at the stabs and jaws. Heat and humidity pit them, and a pitted stab makes resistance, then heat, then one dead leg. A unit that hums and will not start, or a compressor pulling on one leg, is often a burned disconnect. They are cheap and we stock them. Check the block is not in upside down, since some are directional.

How do I make it safe to work on?

Shut off the breaker at the panel and pull the disconnect block. That is it. Verify dead with a meter at the line side of the contactor before your hands go in. Never poke at capacitor terminals with a screwdriver. A run capacitor stays wired across the motor windings, so cutting power bleeds it off through the winding within seconds.