The Siemens A2A200NRW200ECB is an enclosed circuit breaker from the Formula A2A line, rated 200 A and housed in a Type 3R enclosure. Type 3R means it is rainproof and sleet-resistant — suited for outdoor service-entrance or feeder applications where the breaker must be protected from weather but not submerged. The enclosure integrates the breaker and the outer shell into one assembly, so it arrives ready for line and load connections without separate panel mounting.
What the 200 A rating means in practice
The 200 A continuous rating is the breaker's frame size — the maximum current it is designed to carry without tripping under normal load. In a Type 3R enclosure, that rating holds for outdoor ambient conditions, but the thermal performance assumes free air circulation around the enclosure; stacking enclosures or mounting in a confined alcove will reduce the effective ampacity. For a service-entrance or feeder circuit, the 200 A frame typically feeds a downstream panelboard or a large motor control center, so coordination with upstream overcurrent protection should be checked during commissioning.