The thermal-magnetic trip unit is a TM220, set for line protection (ATFM). The continuous current rating (In) is 20 A, with an adjustable overload protection range (Ir) from 14 A to 20 A. Short-circuit protection (Ii) is fixed at 16 times In — 320 A magnetic pickup. This is a fixed-trip configuration; the overload band is the only field-adjustable parameter.
Deployment Context
The suffix ZD00 indicates a nut keeper kit included for DC Power OEM applications in China — a packaging variant, not a functional change. The 3VA1 frame is a standard IEC form factor, so it fits alongside other 160 A frame accessories (auxiliary contacts, shunt trips, undervoltage releases) from the same series.