Pressure switch alarm (PSA)
1- Product Overview
The PSA Series contains two SPDT switches. The PSA10 adjustable pressure sensitivity to provide an alarm response between 4 and 20 psi. It is factory set to respond at 4–8 psi on rising or falling Pressure. The PSA40 adjustable pressure sensitivity to provide an alarm response between 15 and 55 psi. It is factory set for use in a nominal 40 psi system. PSA120 is factory set to respond at 120 psi on rising pressure and 20 psi at decreasing pressure.
| Warning |
| Installation must be performed by qualified personnel and in accordance with all national and local codes and ordinance. |
2- Standard
- Standard for Installation of Sprinkler System
- One-And Two-Family Dwellings and Manufactured Homes Installation of Sprinkler Systems
- Standard for The Installation of Sprinkler System in Low-Rise Residential Occupancies
- National Fire Alarm Code
NFPA-13
NFPA-13D
NFPA-13R
NFPA-72
3- Features
Service Environment: Indoor or Outdoor Use, all parts have corrosion resistant finishes
- Temperature Range: 0℃ – 80℃
- Cover Tamper: Tamper Resistant Screws
- Connection: 1/2-14NPT Thread
- Electrical Ratings: 125/250VAC 15A
- Double micro switch design
Double micro switch design reduces the risk of false signal delivery caused by tamper switch malfunction. Meanwhile, multi-signal output can meet different requirement ofmore customers.
- Double pressure-sensing design
High pressure alarm and low pressure alarm can be realized by one device.
- IP Grade: IP65
Dust proof and water proof, good guarantee for the inner structure safety.
4- Design & Dimensions
| Part No. | Part | Material |
| 1 | Cover | Die-Cast Aluminum |
| 2 | Micro Switch | Carbon Steel Q235 |
| 3 | Adjustment Knob | PA66+GF30 |
| 4 | Pressing Rod | PA66+GF30 |
| 5 | Compression Spring | 65# Steel |
| 6 | Gasket | CR Foam Cotton |
| 7 | Bottom Cover | Nylon |
| 8 | Pressure-bearing Part | PA66+GF30 |
| 9 | Pressure-sensitive Diaphragm | EPDM |
| 10 | Micro Switch Bracket | Carbon Steel Q235 |
5- Installation & Application
Preparation Before installation
– Read the user manual carefully before installation. The manufacturer is not liable for the damage caused by improper installation.
| WARNING |
– Before installation, check the nominal diameter, temperature range, pressure range and medium, do not install if the technical parameter of the pressure switch alarm cannot meet the requirement of the field. – Installation must be performed by qualified personnel and in accordance with all national and local codes and ordinances. – Turn off electrical power before installation or maintenance, otherwise will cause serious injury or casualties. – Do not use in inflammable and explosive environment, otherwise will cause serious injury or casualties. |
a) Installation
Use a special key to disassemble the tamper proof screws.
Wire across the electric outlet and connect with the terminals of the supervisory switch.
Connect with the appropriate terminal.
| CAUTION |
– Do not tighten by grasping the switch enclosure. Apply the wrench on the flat above the threaded male connection only. Do not over tighten to avoid possible damage to the device. – For sealing purpose, apply Teflon tape to the threaded male connection on the device only. Using sealing compounds can block the pressure port inlet and result in improper device operation and damage to equipment. |
b) Wiring Instructions
Use the special key to disassemble the tamper proof screws. Break off the knockout plug with screwdriver, with sufficient force applied to the slot on the edge of the knockout carefully. Wire across the knockout hole and connect with the terminals of the micro switch. Connect with the appropriate terminal. Test and make sure that the device can work properly.
c) Adjustment Instruction
Turn the adjustment knob clockwise to increase the pressure trigger point, and anticlockwise to reduce the pressure trigger point. Aligning the upper surface of the adjustment knob same as the scale value, verify the pressure with pressure gauge.
Each device is equipped with two separate micro switches which can work independently and set to any specific value within the designed adjustment value range.
| ATTENTION |
Different Pressure Adjustment Options: PSA10: adjustable between 4 and 20 PSI (0.03-0.14MPa) PSA40: adjustable between 15 and 55 PSI (0.10-0.38MPa) PSA120: adjustable between 20 and 120 PSI (0.14-0.82MPa) |
Typical Electrical Connection
Side and Top View
Installation Position
1. Alarm Valve 2. Ball Valve (normally close) 3. Ball Valve (normally open)
4. Drain Valve 5. Decelerator 6. Strainer 7. Alarm 8. Pressure switch
Wiring Instructions
Use the special key to disassemble the tamper proof screws. Break off the knockout plug with screwdriver, with sufficient force ap.plied to the slot on the edge of the knockout carefully
| CAUTION |
For sealing purpose, apply Teflon tape to the threaded male connection on the device only. Using sealing compounds can block the pressure port inlet and result in improper device operation and damage to equipment . |
d) Test Instruction
The operation of the pressure switch alarm should be tested after installation in accordance with the applicable NFPA codes and standards and/or the authority having jurisdiction.
Method 1:
Open the inspector’s end-of-line test valve, or open the drain valve of the alarm check valve assembly (Fig. 9, Part No. 4). Allow enough time to fulfill the decelerator with water, then the pressure switch alarm should output signal.
Method 2:
Remove the locking device of the ball valve (Fig. 9, Part No.3) and close it. Open the ball valve (Fig. 9, Part No. 2). Allow enough time to fulfill the decelerator with water, then the pressure switch alarm should output signal. Turn these two ball valves to original position after testing.
| NOTE |
| The above tests may activate any other circuit closer or motor gongs that are present on the system. |
e) Transportation and Storage
Turn the adjustment knob clockwise to increase the pressure trigger point, and anticlockwise to reduce the pressure trigger point. Aligning the upper surface of the adjustment knob same as the scale value, verify the pressure with pressure gauge.
Each device is equipped with two separate micro switches which can work independently and set to any specific value within the designed adjustment value range.