Milbank MTB-P and MTB-P48 4-7 Terminal Ring-Type Small Closing Plate Link Bypass 1-200 Ampere Main Pullout

Terminal count on the MTB-P ring-type socket is set by the utility's metering form, not by the load. The 4 terminal version (224MTB-P) is the common single phase 3 wire socket. The 5 terminal (225MTB-P) adds the fifth jaw used for network or certain 3 wire delta metering. The 7 terminal (227MTB-P) is used for 3 phase 4 wire metering. Get the required terminal count from the serving utility's meter socket specification before ordering, because the jaw arrangement is not field convertible.

Universal mounting is offered on the 4 terminal and 7 terminal sockets in both voltage classes: U224MTB-P and U224MTB-P48 for 4 terminal, U227MTB-P and U227MTB-P48 for 7 terminal. The 5 terminal socket is offered in the standard mounting only. Property managers standardizing a run of meter positions across mixed existing backboards usually want the U prefix versions for that reason.

Self-contained means the full service current passes through the meter and its socket jaws, so the MTB-P is applied where the service is within the socket's own ampere class. It is not a transformer-rated socket, so it does not take an instrument-transformer meter and is not the part to use where the utility is metering through CTs. For a CT-metered service you need a transformer-rated meter socket or a CT cabinet plus a transformer-rated socket instead.

Link bypass lets the utility or an electrician shunt the meter jaws with a bypass link so the meter can be pulled without dropping load to the building. The MTB-P is a link bypass socket, which is what many utilities require on commercial and multi-family services where an outage to change a meter is not acceptable. If your utility spec calls for a non-bypass or a lever (horn) bypass socket instead, this is not the socket to order.

Ring type means the meter is retained by a separate sealing ring clamped over the meter flange, and the socket has a small closing plate rather than a full ringless cover. A ringless cover will not work on it, and the sealing ring is the piece the utility seals. Utilities are specific about ring versus ringless, so confirm which style your serving utility accepts before ordering, and plan to have the sealing ring on hand at install.

No breaker is included. The MTB-P is a main pullout socket, meaning the disconnecting means is a pullout block rather than a circuit breaker, so it is a meter socket with pullout disconnect and not a meter-main combination with branch breaker spaces. If the job needs metering plus branch distribution in one enclosure, a meter-main combination or a separate panelboard downstream is what you want.