Thermal magnetic protection with adjustable trip range
The ABB A1A020TW-1 is a Type Thermal Magnetic moulded-case circuit breaker from the A1A 100 series, fitted with a TMF 20-400 trip block — the adjustable thermal-magnetic unit covers a 20 A to 400 A continuous current range, letting you set the overload and short-circuit protection threshold to match the downstream load without swapping the breaker frame.
EOL hot — last-time-buy sourcing reality
Availability is limited to independent surplus and broker stock. Quantities are lot-specific — confirmed at RFQ against your BOM line.
What the TMF 20-400 trip block means for coordination
The TMF designation indicates a thermal-magnetic trip unit with a fixed magnetic (instantaneous) pickup and an adjustable thermal (overload) element. The 20-400 A range lets you dial in the continuous current rating via the trip dial — useful when the same breaker frame is used across multiple motor or feeder sizes in a panel, reducing spare-part variety.