Uploaded September 2024 | Updated September 2026, 22 hours ago
Question: How do I Replace a Series A3000 Photohelic® Pressure Switch/Gage relay pack?
Answer: The only tools you will need are a Philips screwdriver and replacement relay pack. You can order a replacement relay pack by calling customer service or technical support at +1.800.872.9141. Please be ready with a full part number for your A3000 so we can get you the correct relay pack you need. Relay packs can be replaced in 6 easy steps:
1. Remove plastic cover
2. Disconnect white communication cable
3. Remove relay pack
4. Replace with new relay pack
5. Reconnect white communication cable
6. Replace plastic cover
The Series A3000 Photohelic® Switch/Gages function as versatile, highly repeatable pressure switches combined with a precise pressure gage employing the time-proven Magnehelic® gage design. The Photohelic® switch/gage measures and controls positive, negative or differential pressures of air and compatible gases. Standard models are rated to 25 psig (1.7 bar) with options to 35 (2.4) or 80 (5.5 bar) psig. Two phototransistor actuated, DPDT relays are included for low/high limit control. Easy to adjust set point indicators are controlled by knobs located on the gage face. Individual set point deadband is one pointer width - less than 1% of full scale. Set points can be interlocked to provide variable deadband - ideal for control of fans, dampers, etc. Gage reading is continuous and unaffected by switch operation, even during loss of electrical power. Choose from full scale pressure ranges from a low 0-.25 in (0-6 mm) w.c. up to 30 psi (21 bar). To learn more or order visit dwyer-inst.com/Product/Pressure/DifferentialPressure/Gage-Switches-Dial/SeriesA3000?Query=a3000#literature
Question: How do I Replace a Series A3000 Photohelic® Pressure Switch/Gage relay pack?
Answer: The only tools you will need are a Philips screwdriver and replacement relay pack. You can order a replacement relay pack by calling customer service or technical support at +1.800.872.9141. Please be ready with a full part number for your A3000 so we can get you the correct relay pack you need. Relay packs can be replaced in 6 easy steps:
1. Remove plastic cover
2. Disconnect white communication cable
3. Remove relay pack
4. Replace with new relay pack
5. Reconnect white communication cable
6. Replace plastic cover
The Series A3000 Photohelic® Switch/Gages function as versatile, highly repeatable pressure switches combined with a precise pressure gage employing the time-proven Magnehelic® gage design. The Photohelic® switch/gage measures and controls positive, negative or differential pressures of air and compatible gases. Standard models are rated to 25 psig (1.7 bar) with options to 35 (2.4) or 80 (5.5 bar) psig. Two phototransistor actuated, DPDT relays are included for low/high limit control. Easy to adjust set point indicators are controlled by knobs located on the gage face. Individual set point deadband is one pointer width - less than 1% of full scale. Set points can be interlocked to provide variable deadband - ideal for control of fans, dampers, etc. Gage reading is continuous and unaffected by switch operation, even during loss of electrical power. Choose from full scale pressure ranges from a low 0-.25 in (0-6 mm) w.c. up to 30 psi (21 bar). To learn more or order visit dwyer-inst.com/Product/Pressure/DifferentialPressure/Gage-Switches-Dial/SeriesA3000?Query=a3000#literature
