CCS 6900G/P pressure switch

Electrical connection and grounding

Electrical connections must be made under power-off conditions. Before operation, it is necessary to check whether there is a multi circuit power supply to ensure that all relevant power sources have been isolated. The wiring should comply with NEC and all applicable specifications. The conductor is located within the male conductor connection, and the conduit casing should be tightened with a wrench or subjected to a maximum torque of 12 ft.lb. When wiring, as many wires as possible should be retained as service loops for subsequent maintenance and replacement.

Proper grounding is crucial. Grounding must be completed using the provided grounding wire. Users are responsible for ensuring the effectiveness of ground fault protection and equipotential bonding functions, or adopting other equally effective methods. If the system requires a terminal box kit, corresponding accessories can be optionally provided. For DPDT switches, the two sets of contacts should be wired separately to avoid confusion at the common end. If the load is inductive or capacitive, contact protection and arc extinguishing measures should be considered to extend the electrical life.

Pressure setting and adjustment

The pressure setting of CCS 6900G/6900P pressure switch is externally adjustable, but the factory set model is not suitable for on-site adjustment. Before adjustment, if the electrical circuit cannot be used for testing, the power should be disconnected and a suitable circuit tester or light box should be used to determine the contact status. Release the maintenance cover, insert a screwdriver into the adjustment screw slot, rotate clockwise to increase the set value, and counterclockwise to decrease the set value. After the adjustment is completed, tighten the maintenance cover again, reconnect the circuit, apply a maximum torque of 12 ft.lb, and then restore the power supply.

When adjusting, gradually approach the target value and avoid a large rotation at once. It is recommended to read the action point and reset point after the system pressure stabilizes, and confirm whether the hysteresis meets the requirements. For critical applications, the set values, adjustment dates, and operators should be recorded. If the switch is used for alarm or interlocking, actual pressure verification should be performed after adjustment, rather than relying solely on electrical testing. Multiple verifications can confirm the repeatability accuracy.

Common troubleshooting

1. The switch does not operate. Firstly, confirm whether the system pressure has reached the set point. If the pressure is normal but the switch does not operate, check whether the pressure port is blocked, whether the sensing element is stuck, and whether the adjusting screw is loose or damaged. In terms of electrical aspects, check whether the wiring between the common terminal and the normally open/normally closed terminal is correct, whether the contacts are oxidized, and whether the load is disconnected. For the gold contact version, it is generally reliable under low-level signals, but overloading may cause permanent damage.

2. Switch misoperation. Possible reasons may include system pressure fluctuations, pump start stop impacts, water hammer, vibration, set point too close to working pressure, excessive installation torque causing shell stress, sealing material entering pressure channels, contact bounce, or external electromagnetic interference. Damping should be increased, set points adjusted, installation rigidity improved, or shielded cables used.

3. Port or thread leakage. Check if the NPT threads match, if the sealing compound or Teflon tape is appropriate, and if the installation torque is within 12 ft.lb. Insufficient torque can cause leakage, while excessive torque can damage threads. If using tapered pipe threads, ensure that the engagement length is sufficient.

4. Poor contact of the contacts. Check if the wiring terminals are loose, if the wires are oxidized, and if the contacts are burned due to overload. Confirm that the actual load does not exceed the rated value. For DC loads, special attention should be paid to arc extinguishing capability, and if necessary, freewheeling diodes or RC absorption circuits should be added.

5. Grounding or interference issues. If the system experiences random misoperation, check whether the ground wire is reliably connected, whether the cable is laid in parallel with the power line, and whether the shielding layer is single ended grounded. In a multi circuit system, it should be confirmed that there is no mixing of wires from different circuits.

6. The adjustment is invalid. If there is no change in the set point after rotating the adjustment screw, it may be due to the factory setting being locked, the adjustment mechanism being damaged, or the pressure channel being blocked. At this point, the operation should be stopped and qualified service personnel should be contacted. Do not forcefully rotate to avoid damaging the internal mechanism.

7. DPDT second group contacts are abnormal. Check the BLACK, YELLOW, PURPLE wiring and confirm the second set of common and normally open/closed terminals. If the first group is normal and the second group is abnormal, it may be due to wear and tear of the internal linkage mechanism or wiring errors.