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Mcdonnell & Miller General Purpose Liquid Flow Switch, Series FS250 - Flow Switches
Mcdonnell & MillerFlow Switches

Mcdonnell & Miller General Purpose Liquid Flow Switch, Series FS250

McDonnell & Miller Flow Switches.

SKU 3G-OTH-02711

Also listed as: FS 250 · FS-250

Brand
Mcdonnell & Miller
Item
General Purpose Liquid Flow Switch, Series FS250
Part Number
FS250
Category
Flow Switches
Available to Order
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Local availability & support — Singapore

Local office
20 Woodlands Link #09-05, Singapore 738733
Phone
+65 8878 8355
Payment
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Technical Specifications

Mcdonnell & Miller
Manufacturer Part Number
FS250

Technical Documents

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Mcdonnell & Miller Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

McDonnell & Miller Flow Switches.

Frequently Asked Questions

What is the McDonnell & Miller FS250 flow switch used for?

The McDonnell & Miller FS250 flow switch is used to detect liquid flow or no-flow in pipelines, typically in HVAC, boiler, and industrial process systems. It activates an electrical signal when flow starts or stops, enabling pump control, alarm triggering, or equipment protection.

What are the specifications of the McDonnell & Miller FS250?

The FS250 has a 1-inch NPT connection, two electrical knock-outs for wiring from either end, and a sensitivity adjusting screw for easy flow adjustment. It is a single-pole, double-throw (SPDT) switch designed for liquid flow applications.

Where to buy the McDonnell & Miller FS250 in Singapore?

You can source the McDonnell & Miller FS250 flow switch through 3G Electric in Singapore. We handle logistics, customs clearance, and delivery to your site. Contact us for pricing and lead time on this item.

How to install the McDonnell & Miller FS250 flow switch?

Install the FS250 in a horizontal pipe section with the flow arrow aligned correctly. Wire the SPDT switch through the electrical knock-outs per your control circuit. Adjust the sensitivity screw to set the flow activation point. Always follow local electrical codes and the manufacturer's manual.

Used in

Common applications for Mcdonnell & Miller
Boiler systems — McDonnell & Miller FS4-3T3-1 flow switch for low-water cutoff and pump protection in 1-inch piping.
Pump control — McDonnell & Miller FS8-W flow switch for detecting flow in 1-inch lines to prevent dry running.
HVAC cooling water — McDonnell & Miller FS6-3/4 flow switch for monitoring flow in 3/4-inch chilled water circuits.
Process piping — McDonnell & Miller FS5-3/4 brass flow switch for hot water applications up to 250°F.
Industrial liquid monitoring — McDonnell & Miller FS6-W-1 flow switch for 1-inch lines with high locked-rotor rating.
Small pipe systems — McDonnell & Miller FS-1 flow switch for 1/2-inch lines in liquid circuits requiring flow detection.
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Mcdonnell & Miller Products

3G Electric supplies Mcdonnell & Miller flow switches. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

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Compatible alternatives & equivalents

Cross-referenced by specification & description
Siemens
Siemens
2-way flanged zone valve with spring return and normally closed operation. Features a 1 in flanged port connection and 24V AC/DC actuator voltage. Proportional signal control for modulating flow in HVAC and industrial fluid systems
Siemens
Siemens
Two-way, spring return, normally closed zone valve with 1 in Union NPT connections and 24V AC floating signal actuator. Used in hydronic HVAC systems to regulate fluid flow in heating or cooling zones
Siemens
Siemens
This Siemens 2-way flanged zone valve features a 1-1/2 in flanged port connection and a 24V AC/DC actuator. It is spring return, normally closed (NC), and accepts a proportional control signal for modulating flow. Suitable for regulating water or glycol in HVAC and fluid control systems
Siemens
Siemens
2-way, spring return, normally closed zone valve with 3/4 in Union NPT connections and 24V AC/DC floating signal actuator. Used in HVAC systems for regulating fluid flow in piping networks
Siemens
Siemens
This Siemens magnetic valve is a 2-way, spring return, normally closed (NC) valve with a floating signal. It features a 2 in Union NPT port connection and operates on 20 to 30V DC actuator voltage. Suitable for on/off or floating control in HVAC and industrial fluid systems, it provides fail-safe operation upon power loss
Siemens
Siemens
2-way, spring return, normally closed zone valve with 1-1/4 in Union NPT connections. Operates on 24V AC floating signal. Suitable for regulating fluid flow in HVAC zone control applications

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