继电器外壳应清洁无灰尘。

Relay shell should be clean.

youdao

介绍了一种具有热过载报警不脱扣功能的CM 3塑料外壳式断路器，其将热过载继电器的部分功能与MCCB的功能有机地结合在一起。

CM3 molded case circuit breaker (MCCB) with thermal overload alarm but non-release function was introduced. It integrates part function of thermal overload relay and function of MCCB.

youdao

MCP应符合NEMA 12日（北美应用）或IP - 54的外壳充分继电器的大小，人机界面，PLC机架等所需的洁净室系统的运作。

The MCP shall be a NEMA 12 (for North American applications) or IP-54 enclosure adequately sized for all of the relays, PLC rack, HMI, etc. required for the operation of the clean room system.

youdao