Ashcroft
Ashcroft B424 Pressure Switch SPDT 6-60 psi 1/4" FNPT NEMA 13 3 4 4X
Diaphragm-actuated SPDT pressure switch covers 6 to 60 psi with 1.0 to 3.5 psi differential and NEMA 13, 3, 4, 4X rating
- Pressure range 6 to 60 psi for versatile control
- SPDT contact form enables single-pole double-throw switching
- NEMA 13, 3, 4, 4X ratings protect against harsh environments
- 15 A AC rating at 125, 250, 480 V handles heavy loads
- Diaphragm actuation with 1.0 to 3.5 psi differential ensures precise operation
Ashcroft B424 Pressure Switch
The Ashcroft B424 is a diaphragm-actuated pressure switch designed for industrial control circuits. It provides a standard SPDT contact that opens or closes when system pressure moves through the adjustable 6 to 60 psi range. The switch mounts via a 1/4 inch FNPT port and carries NEMA 13, 3, 4 and 4X enclosure ratings for dust, water and oil resistance. Factory on/off points are set at 90 percent of the selected range.
Suited for pump and compressor control
This unit suits technicians wiring motor starters or contactors that need a reliable pressure signal in hydraulic or pneumatic systems up to 60 psi. The SPDT form allows either normally-open or normally-closed logic without rewiring. Buyers who need a differential narrower than 1.0 to 3.5 psi or a pressure range above 60 psi should look at a different model. The switch is not intended for direct high-current motor loads without a contactor.
Wiring and mounting notes
The switch carries AC ratings of 15 A at 125 V, 250 V and 480 V, plus DC ratings of 0.25 A at 250 V, 0.5 A at 125 V and 6 A at 30 V, so pilot-duty control circuits are the appropriate application. A 1/4 inch FNPT fitting connects the diaphragm to the process line. The NEMA 4X rating permits outdoor or wash-down installation without additional enclosures. No external power supply is required for the switching action itself.
Highlights
- Pressure range 6 to 60 psi for versatile control
- SPDT contact form enables single-pole double-throw switching
- NEMA 13, 3, 4, 4X ratings protect against harsh environments
- 15 A AC rating at 125, 250, 480 V handles heavy loads
- Diaphragm actuation with 1.0 to 3.5 psi differential ensures precise operation
Specifications
| Brand | ASHCROFT |
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Questions about this item
What size process connection does the B424 need on my piping?
The switch has a single 1/4 in FNPT port, so your piping must provide a matching 1/4 in male NPT thread.
Will the SPDT contacts handle the 250 V control circuit I already use?
Yes — the contacts are rated 15 A at 250 V AC and 0.25 A at 250 V DC, covering typical 250 V control loads.
How can I verify the switch actuates at the correct pressure after installation?
Apply pressure and confirm the contacts change state between 6 and 60 psi; the differential will be 1.0 to 3.5 psi and the factory setting is at 90 percent of range.
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