Carey.Mossop
New member
285.23 permits a Type 1 SPD to be connected to the supply side of the service disconnect as permitted in 230.82(4). These Type 1 SPDs are often connected directly to the load terminals of a meter or the line side of the service disconnect overcurrent device without an additional overcurrent protective device. (August 2009 EC&M Article by Mike Holt)
A Type 1 SPD is also permitted to be connected as specified in 285.24, in other words, anywhere on the load side of the service disconnect overcurrent device.
I have heard people say that a Type 1 SPD does not need an overcurrent protective device when connected on the load side of the service disconnect, i.e. it can be field wired without an overcurrent protective device protecting the conductors the SPD is being fed with. I do not believe this is true. Article 240.4 says that conductors other than flexible cords, flexible cables, and fixture wires shall be protected against overcurrent in accordance with their ampacities specified in 310.15. In other words if the Type 1 SPD is connected with #10 AWG conductors, the conductors must be protected by a 30 ampere fuse or circuit breaker.
Am I wrong? Is there any rule in the NEC that allows an SPD to be connected on the load side of a service disconnect without an overcurrent protective device?
A Type 1 SPD is also permitted to be connected as specified in 285.24, in other words, anywhere on the load side of the service disconnect overcurrent device.
I have heard people say that a Type 1 SPD does not need an overcurrent protective device when connected on the load side of the service disconnect, i.e. it can be field wired without an overcurrent protective device protecting the conductors the SPD is being fed with. I do not believe this is true. Article 240.4 says that conductors other than flexible cords, flexible cables, and fixture wires shall be protected against overcurrent in accordance with their ampacities specified in 310.15. In other words if the Type 1 SPD is connected with #10 AWG conductors, the conductors must be protected by a 30 ampere fuse or circuit breaker.
Am I wrong? Is there any rule in the NEC that allows an SPD to be connected on the load side of a service disconnect without an overcurrent protective device?