Einführung
This manual provides detailed instructions for the installation, operation, and maintenance of your JahyShow Air Compressor Pressure Switch Control, model BM-Y157. This heavy-duty 26A single-port pressure switch is designed to regulate air pressure in compatible air compressors, helping to optimize energy consumption and ensure safe operation.
Sicherheitshinweise
WARNUNG: Always disconnect power to the air compressor and ensure it is fully depressurized before installing, servicing, or adjusting the pressure switch. Failure to do so can result in serious injury or death.
- Um elektrische Gefahren zu vermeiden, stellen Sie sicher, dass alle elektrischen Verbindungen sicher und ordnungsgemäß isoliert sind.
- Installation should be performed by a qualified individual if you are unsure about any steps.
- Überschreiten Sie nicht die maximale Lautstärketage und amperage ratings specified for this device.
- Tragen Sie während der Installation und Wartung geeignete persönliche Schutzausrüstung (PSA).
Produkt überview
The JahyShow BM-Y157 pressure switch is a robust component for air compressor systems. It features a single 1/4" NPT female port for connection and an integrated ON/OFF switch lever for manual control. An unloader valve is also included to release air pressure from the compressor head when the motor stops, facilitating easier restarts.

This image displays the JahyShow Air Compressor Pressure Switch, showing its main body, pressure port, and the ON/OFF lever.
Hauptmerkmale:
- Single 1/4" NPT port connection manifold.
- Suitable for 90-125 Psi 26A air compressors.
- Heavy-duty 26A contacts for extended durability in demanding applications.
- Constructed from high-quality, corrosion-resistant materials for long mechanical life.
- Integrated ON/OFF switch lever for manual control.
- Includes an unloader valve.
Technische Daten
| Modellnummer | BM-Y157 |
| Default On (Cut-in) Pressure | 90 PSI |
| Default Off (Cut-out) Pressure | 120 PSI |
| Einstellbarer Druckbereich | Min On: 35 PSI, Max Off: 150 PSI |
| Differential | 30-40 PSI |
| Pole Rating | 2 Pole |
| Single Phase Rating | 20 Amps at 120V AC / 12 Amps bei 240 V AC |
| Three Phase Rating | 9.6 Amps bei 240 V AC |
| Maximale Lautstärketage | 240 V Wechselstrom |
| Porttyp | 1/4" NPT Single Female Port |
| Betriebsmodus | EIN-AUS |
| Kontakttyp | Normalerweise geschlossen |
| Internationale Schutzbewertung | IP54 |
| Material | Plastik |
| Artikelgewicht | 12.7 Unzen |
Setup und Installation
Follow these steps for proper installation of the pressure switch:
- Stromabschaltung: Ensure the air compressor is unplugged from its power source and completely depressurized before beginning any work.
- Alten Schalter entfernen (falls zutreffend): Carefully disconnect all wiring from the existing pressure switch. Note the wiring configuration for correct re-connection. Unscrew the old pressure switch from the air compressor manifold.
- Prepare New Switch: Apply thread sealant, such as PTFE (Teflon) tape, to the 1/4" NPT male threads of the new JahyShow pressure switch. Wrap the tape clockwise around the threads for a secure, leak-free seal.
- Neuen Schalter installieren: Screw the new pressure switch into the manifold port on your air compressor. Hand-tighten first, then use a wrench to tighten securely. Do not overtighten, as this can damage the threads or the switch housing.

This image shows the underside of the pressure switch, clearly displaying the 1/4 inch NPT single female port for connecting to the air compressor manifold.
- Drahtverbindungen: Connect the electrical wires to the appropriate terminals on the new switch. Refer to the original wiring configuration or your compressor's manual for correct connections. This switch is rated for 20A at 120V AC or 12A at 240V AC (single phase). Ensure all connections are tight and insulated.
- Auf Lecks prüfen: Once installed and wired, repressurize the air compressor system. Apply soapy water to all connections, especially around the new switch, to check for any air leaks. Bubbles indicate a leak that needs to be addressed.
Bedienungsanleitung
The pressure switch automatically controls the air compressor's motor based on the tank pressure. It also features a manual ON/OFF lever.

Eine direkte Front view of the pressure switch, detailing the central pressure connection point and the red-tipped ON/OFF lever for manual control.
- Ein-/Ausschalten: Use the integrated ON/OFF switch lever to manually control the compressor. Move the lever to the 'ON' position to allow automatic operation. Move it to the 'OFF' position to stop the compressor and prevent automatic restarts.
- Automatische Operation: When the lever is in the 'ON' position, the compressor will automatically start when the tank pressure drops below the factory-set cut-in pressure (default 90 PSI). It will then run until the tank pressure reaches the factory-set cut-out pressure (default 120 PSI), at which point it will automatically shut off.
- Druckeinstellung: The cut-in and cut-out pressures are adjustable within the specified range (Min On: 35 PSI, Max Off: 150 PSI). To adjust, locate the adjustment screw (typically under a protective cover or accessible from the top of the switch). Turn the screw clockwise to increase both cut-in and cut-out pressure settings, and counter-clockwise to decrease them. Make small adjustments and test the system's operation to achieve desired pressure levels.
Wartung
Regular maintenance helps ensure the longevity and reliable operation of your pressure switch:
- Inspektion: Periodically inspect the pressure switch for any visible signs of wear, damage, cracks, or corrosion.
- Elektrische Anschlüsse: Ensure all electrical connections remain tight and free from corrosion. Loose connections can lead to overheating or intermittent operation.
- Sauberkeit: Keep the switch clean and free from dust, debris, and excessive moisture. A clean, dry environment is crucial for electrical components.
- Dichtigkeitsprüfungen: Regularly check for air leaks around the switch and its connections using soapy water. Address any leaks promptly to maintain compressor efficiency.
Fehlerbehebung
If you encounter issues with your pressure switch, refer to the following common problems and solutions:
- Compressor Does Not Start:
- Ensure the ON/OFF lever on the switch is in the 'ON' position.
- Verify that the air compressor is plugged in and receiving power.
- Prüfen Sie alle Kabelverbindungen auf Lockerheit oder Beschädigung.
- Confirm that the tank pressure is below the cut-in setting.
- Compressor Does Not Stop:
- Ensure the ON/OFF lever is in the 'ON' position.
- Verify that the tank pressure has reached the cut-out setting.
- Inspect the pressure switch for internal damage or stuck contacts. (Caution: Disconnect power before inspection.)
- Check for air leaks in the system, which might prevent the pressure from building up to the cut-out point.
- Pressure Fluctuates Erratically:
- Check for air leaks in the system, including the tank, hoses, and fittings.
- Inspect the unloader valve for proper function; it should close completely when the compressor is running.
- Ensure the pressure adjustment screw is secure and not vibrating loose.
Garantieinformationen
JahyShow products are designed for durability and performance. For specific warranty details regarding your BM-Y157 Air Compressor Pressure Switch Control, please refer to the product packaging or contact JahyShow customer support directly. Keep your purchase receipt as proof of purchase.
Unterstützung
For technical assistance, product inquiries, or to report any issues, please visit the official JahyShow store on Amazon or contact their customer service directly through the provided channels on their store page.
JahyShow Store Link: Visit the JahyShow Store