The Qualitrol 930 is a multi-function electronic pressure monitor designed to detect and respond to both rapid pressure rise and slow (static) pressure changes in transformer systems. It is commonly applied on main transformer tanks and load tap changer (LTC) compartments to provide alarm and trip functions that help protect equipment from dangerous pressure events.
This device uses electronic pressure sensors that continuously monitor tank pressure and output a signal proportional to the measured value. It combines rapid pressure rise detection with static pressure monitoring and includes seal-in relay functionality. Field-adjustable set points allow customization of sensitivity for both fast and slow pressure events. Local LED indicators show status, while continuous analog outputs support remote indication or SCADA integration. Single-sensor and multi-sensor versions are available; multi-sensor models can use logic schemes (such as 2-out-of-3) to help reduce nuisance trips. Sensors are suitable for both oil and gas spaces and can be mounted via 1/4"-18 NPT or with retrofit adapters for existing Qualitrol 900/910 installations.
| Specification | Details |
|---|---|
| Model Series | Qualitrol 930 |
| Function | Rapid and static pressure monitoring with alarm/trip |
| Pressure Range | 0 to 30 PSIG (0 to 2 bar) |
| Sensor Mounting | 1/4"-18 NPT pressure input port |
| Number of Switches | Single sensor: up to 3 SPDT; Multi-sensor: up to 9 SPDT |
| Relay Contacts | Fast pressure, slow pressure, and power status options |
| Analog Output | 0-1 mA or 4-20 mA (for remote/SCADA) |
| Input Power | Universal options including 85-265 VAC 50/60 Hz or 110-370 VDC |
| Cable Length | Up to 750 ft (228.6 m) max |
| Ambient Temperature (Sensor/Cable) | -40°C to 85°C |
| Ambient Temperature (Control Board) | Approx. -30°C to 72°C |
| Protection / Indication | Local LEDs for actuation and power status |
Primarily used in electric power utilities and industrial substations for protection of power transformers and load tap changers. Supports condition-based maintenance and asset protection programs.
Mechanical rapid pressure rise devices can produce nuisance trips or lack continuous remote monitoring. The 930 helps address these through adjustable sensitivity, multi-sensor logic options, continuous analog outputs, and clear local indication with selectable momentary or seal-in operation.
Suitable as an electronic upgrade or replacement for mechanical Qualitrol 900/910 rapid pressure rise relays and similar sudden pressure devices, including retrofit mounting options.
We supply genuine Qualitrol pressure monitoring equipment and provide practical support for selection and application on transformer protection systems.
Typical production and delivery time is 6-8 weeks.
Please provide details on single or multi-sensor preference, power supply requirements, desired analog output, mounting needs, and quantity for a customized quotation.
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