SENTRON 3WL air circuit breakers (ACB)

A 3WL is needed in these cases:

• Current above 1600 A: the 3VA27 reaches 1600 A and the 3WL reaches 6300 A.
• Category B and a withdrawable version: the air circuit breaker is utilization category B and has a withdrawable version on a guide frame.
• Longer mechanical life: 20,000 cycles for the 3WL10 against 10,000 cycles for the 3VA27.

Conversely, at 630 A and below the 3VA2 offers up to 200 kA at 415 V against up to 66 kA for the 3WL10, so for a small incomer with a very high short-circuit current the 3VA2 is stronger. Between 800 A and 1600 A the 3WL10 and the 3VA27 share a platform and have the same fixed-mounted dimensions. In a new project remember that sizes I to III are in Phase Out Announce status.

In the fixed-mounted version the breaker is installed directly in the switchboard and the auxiliary connectors plug onto the breaker itself. The withdrawable version sits in a guide frame: the laminated contacts are in the guide frame and the blade contacts are on the breaker, it has three positions, connected, test and disconnected, it cannot be moved while ON, and the guide frame can be locked. In return its dimensions are larger, because the guide frame sets the size of the withdrawable version; for example, the 3-pole 3WL10 is 210 mm wide fixed-mounted and 278 mm withdrawable.

On SiePortal Siemens shows the 3WL11 to 3WL13 with 'Phase Out Announce' and the message 'Successor portfolio 3WA', so a phase-out has been announced, but no end-of-delivery date is shown on the Siemens pages. The 3WL10 (size 0) is shown as 'Active Product' on SiePortal. The successor is the SENTRON 3WA. According to catalog LV 13 (02/2025), the 3WA can be installed in an existing 3WL guide frame and can replace the 3WL in a switchboard without additional IEC 61439 testing, provided the technical conditions are the same; the 4000 A vertical connections are an exception and need the option D01. The Siemens configurator converts a 3WL article number directly to a 3WA article number.

On the 3WL10: ETU320 (LI), ETU350 (LSI) and ETU360 (LSIG) with rotary coding switches; ETU650 (LSI) and ETU660 (LSIG) with a display, measurement and communication capability. On the 3WL11 to 3WL13: ETU15B (LI, not available in size III), ETU25B (LSI), ETU27B (LSIG), ETU45B and ETU76B (with a graphic display). If time-graded selectivity is needed, ask for at least the S function, that is LSI; for ground-fault protection G, that is LSIG; and if metering and communication are wanted, the ETU650/660 on the 3WL10 or the ETU45B/76B with the CubicleBUS on the larger sizes.

The 3WL10 (size 0) covers 630 A to 1250 A, has a rated voltage of 690 V, three classes B, N and S up to 66 kA at 415 V, and shares its 3-series and 6-series trip units (ETU320, ETU350, ETU360, ETU650 and ETU660) with the 3VA27; it is shown as 'Active Product' on SiePortal. The 3WL11 to 3WL13 (sizes I to III) reach 6300 A and up to 150 kA, have the ETU15B to ETU76B trip units, go up to 1000 V and 1150 V with options, and are in Phase Out Announce status.

According to the 3WL10 code structure in the Siemens catalog: 3WL10 is size 0; 12 is the maximum rated current of 1250 A; 2 is class N (55 kA at 415 V); AC is the ETU350 (LSI) trip unit without communication and metering; 3 is the 3-pole withdrawable version; 2 is rear horizontal connection; 0AA0 is the fixed end of the code. In the same way 3WL1012-2AC03-0AA0 is the 3-pole fixed-mounted version with front main connections. The 3WL11 to 3WL13 use a different code structure, so use the Siemens configurator for them.