Hvac electrical control panel8/12/2023 The self-protected characteristic of Type E MMPs makes them ideal for fan-array motors, as they do not have to rely on upstream overcurrent protective devices (OCPDs) for branch-circuit protection (Figure 2). Note that Type E MMPs require that specific accessories are installed to maintain this listing, such as line-side insulating barriers and short-circuit trip indicators. One specific type of MMP that has features that are well-suited for fan array applications is a UL 508 Type E MMP, also referred to as “self-protected” because its integral short-circuit protection provides the NEC-required branch-circuit protection for an individual motor. MMPs for arrays are typically installed in a common enclosure. These devices are commonly used with fan arrays because they are compact, relatively inexpensive, and comply with NFPA 70: National Electrical Code (NEC) 430.32(A),which requires separate overload protection for each motor. MMPs are listed under UL 508: Standard for Industrial Control Equipment and consist of a disconnect switch, overload protection, and short-circuit protection. To design the protection schemes for these setups, we must first understand the manual motor protector (MMP). With the increased usage of the fan array design, it is important that electrical engineers understand how to provide proper motor protection for these systems. They also use smaller motors, which are more readily available and easy to replace. Fan arrays provide increased redundancy, a smaller footprint, and less vibration. Air handling unit (AHU) fan arrays have become increasingly popular in the past decade, and it’s not difficult to understand why.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |