POWER GENEX MS25 Proximity (Proxy) Switch

Overview

The POWER GENEX MS25 proximity switch is a hermetically sealed, epoxy-resin-moulded sensing device produced by POWER-GENEX LTD / Daehan Control Tech for position detection and limit switching in industrial control loops. The MS25 uses sealed SPDT Form C contacts with rhodium plating, giving stable operation in dusty, humid and corrosive plant atmospheres where open contact blocks fail early. Its sealed construction also permits installation directly in mechanical enclosures without additional protection.

Engineering and Design

The MS25 is built around a hermetically sealed contact capsule with epoxy resin moulding, so the switching element is fully isolated from the surrounding environment. Contacts are SPDT, Form C, with a maximum operating time of 3.0 ms and a maximum contact resistance of 0.5 ohms, which keeps the signal clean for direct connection to relays, motor starter coils and PLC inputs. The housing is polycarbonate and the standard electrical rating is 1A at 24VDC and 0.2A at 120VAC, with an operating temperature range of -40 to +130 deg C.

In a typical installation the MS25 is secured inside the actuator or machine enclosure and operated by a mechanical cam or flag, so no external mounting rod is needed. The SPDT contact is wired with the common, NO and NC terminals to the control circuit, and because the switch is hermetically sealed it can be mounted in the same compartment as greased mechanisms without contaminating the contact. For valve automation, a cam on the driven shaft actuates the switch at the end positions, and the same unit can be duplicated to signal both open and closed. The operating travel of the switch is short, so the cam profile should be checked before commissioning.

Key Features

• Hermetically sealed SPDT, Form C switching element with rhodium contacts
• Rated 1A at 24VDC and 0.2A at 120VAC for signal-level and pilot-duty circuits
• Maximum operating time 3.0 ms and contact resistance 0.5 ohms
• Operating temperature range -40 to +130 deg C
• Epoxy resin sealed capsule in a polycarbonate housing
• Compact form factor for installation inside valve actuators and machine guards

Applications

The POWER GENEX MS25 proximity switch is used for position proof and limit detection on valve actuators, dampers, access covers, hoists and package equipment in power generation, water treatment, offshore and general process plants. In valve automation, the MS25 is typically mounted inside the actuator enclosure with a mechanical cam, signalling the open and closed positions to the control panel. GCC plants use the MS25 proxy switch as a low-cost replacement for mechanical limit switches where repetitive switching and environmental sealing are the priority.

The MS series brochure also lists the MS-100 and MS-110 models, which carry tungsten contacts and higher ratings of 2A at 24VDC, 3A at 120VAC and 1.5A at 240VAC, with temperature ranges of -40 to +130 deg C and -60 to +125 deg C respectively. Where the plant standard is a valve position monitor rather than a bare switch, the Power Genex LSB series combines the sealed switch elements with an explosion-proof housing and visual open/closed indication. Spare requirements are typically calculated at two units per valve station, covering the open and closed positions of each actuator.

The MS-25 is specified where the switching signal must survive in sealed mechanical enclosures, while the MS-100 and MS-110 models of the same brochure cover higher switched loads. The ratings and terminal configurations are compared on the relevant pages of the Power Genex catalogue, and the same switch body is used across the series, simplifying the fixing arrangement.

Specifications

Why Seven Star LLC

Seven Star LLC is an Oman-based supplier of industrial control and instrumentation spares, sourcing genuine POWER GENEX components and checking every inspected unit before release. The POWER GENEX MS25 proximity switch is supplied with its rated electrical data and manufacturer documentation, supported by a technical team that confirms compatibility with your actuator, valve and control panel wiring.

Call To Action

Submit a formal inquiry through our RFQ page with your actuator model, switch configuration and contact requirements. Our team will confirm the correct POWER GENEX MS25 proximity switch for your application and respond with a detailed quotation.