P78MCB-9300 Johnson Pressure Control Switch – -0.05 to 3 MPA, International Part
The P78MCB-9300 Johnson Pressure Control Switch is a high-precision industrial pressure control device designed for a wide range of control and limit functions. This switch is ideal for hydraulic, pneumatic, and industrial applications, providing reliable monitoring, accurate switching, and durable performance.
Built with phosphor bronze bellows, brass pressure connections, and large silver-nickel contacts, it ensures long-lasting operation under demanding conditions.
Key Features ✅
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✅ Pressure Range (Left Side): -0.5 to 7 bar, Differential 0.6 to 3 bar
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✅ Pressure Range (Right Side): 3 to 30 bar, Differential Manual Reset
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✅ Control or limit function depending on model number
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✅ Alarm contacts included on all models (except P78ALA)
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✅ Durable materials: phosphor bronze bellows, brass connections, die-cast aluminum case
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✅ Weatherproof case and cover – IP54 protection class
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✅ Large silver-nickel contact surfaces for reliable switching
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✅ Wide ambient temperature range: -50 to +55 °C (max +70 °C for 2 hours)
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✅ PED-approved models: -20 to +55 °C
Technical Specifications 📝
| Specification | Value |
|---|
| Part Number |
P78MCB-9300 |
| Pressure Range (Left Side) |
-0.5 to 7 bar |
| Differential (Left Side) |
0.6 to 3 bar |
| Pressure Range (Right Side) |
3 to 30 bar |
| Differential (Right Side) |
Manual Reset |
| Electrical Ratings |
400 Vac A-C: 16(10) A, A-B: 8(5) A, A-D: 8(5) A; 220 Vdc: 12 W (pilot duty only) |
| Material |
Phosphor bronze bellows, brass pressure connections, die-cast aluminum case |
| Contact Surface |
Large silver-nickel |
| Protection Class |
IP54 |
| Ambient Temperature Limit |
-50 to +55 °C (max +70 °C, 2 hrs); PED models: -20 to +55 °C |
Common Symptoms Solved ⚡
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❌ Pressure exceeding system limits
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❌ Failure to trigger alarms on high/low pressure
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❌ Inconsistent or unreliable system pressure monitoring
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❌ Equipment damage due to unregulated pressure
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❌ Manual intervention needed for pressure reset
Shopping Tips 🛒
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✅ Verify system pressure range – Left Side: -0.5 to 7 bar, Right Side: 3 to 30 bar
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✅ Check electrical ratings – Ensure compatibility with your 400 Vac / 220 Vdc system
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✅ Select correct model – Depending on whether you need control or limit functions
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✅ PED approval – Confirm if your application requires PED-compliant models
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✅ Proper installation – Mount securely with recommended connections to prevent leaks and ensure accurate operation
Frequently Asked Questions (FAQ) ❓
Q: What pressure ranges does this switch support?
✅ Left Side: -0.5 to 7 bar, Differential 0.6–3 bar; Right Side: 3 to 30 bar, Differential Manual Reset.
Q: What type of applications can it be used for?
✅ Control or limit functions in hydraulic, pneumatic, and industrial systems.
Q: What materials are used?
✅ Phosphor bronze bellows, brass pressure connections, die-cast aluminum case, silver-nickel contacts.
Q: What electrical ratings does it support?
✅ 400 Vac contact (A-C: 16(10) A, A-B: 8(5) A, A-D: 8(5) A); 220 Vdc, 12 W (pilot duty).
Q: Is this switch weatherproof?
✅ ✅ Yes, IP54 rated with a die-cast aluminum case and cover.
