Description
The UE Precision Sensors LDP1WC-47 is a dedicated low differential pressure switch and monitor designed for gas cabinet exhaust systems, ventilation ducting, and cleanroom air handling architectures. Engineered primarily for the semiconductor and electronics manufacturing industries, this tool prevents false process trips during air balance testing while providing constant electronic diagnostic surveillance.
Commercial Inventory & Procurement Details
| Logistics Parameter | Value / Terms |
| Hardware Condition | New Original (Factory Sealed Surplus) |
| Warranty Period | 12-month comprehensive warranty |
| Availability | In stock (subject to prior sale) |
| Standard Lead Time | Ships within 1 to 2 business days from order confirmation |
| Commercial Pricing | Price subject to market conditions; contact us for a firm quote |
Technical Specifications
The specific structural and electrical parameters of the LDP1WC-47 configuration are detailed below. Always cross-reference your structural mechanical layout against the OEM datasheet prior to field integration.
| Parameter | Value |
| Manufacturer / Brand | United Electric (UE) Precision Sensors |
| Product Series | EchoLine LDP Series |
| Core Architecture | Discrete all-analog solid-state circuitry (No Microprocessor) |
| Indicating Range | 0.2 to 20” Inches Water Column (” WC) |
| Accuracy | \pm 1\% of full-scale range at 20 °C |
| Switch Repeatability | \pm 0.5\% of full scale |
| Switching Output | SPDT Form A Electromechanical Relay (Dry Contacts) |
| Contact Power Rating | 1.0 A at 30 V DC (Resistive) |
| Input Supply Voltage | 12 to 24 V DC |
| Power Consumption | 1.4 W maximum |
| Adjustable Time Delay | Field selectable: 1, 10, 20, or 30 seconds |
| Process Media | Dry air or inert, non-conductive gases |
| Media Connections | Push-to-connect fittings for 0.25” O.D. tubing / Barbed hose fitting |
| Enclosure Standard | 1/16th DIN 43700 panel-mount polycarbonate casing |
| Safety Compliance | UL 508, UL 991, and CE marked |
Engineering Context & Deployment Considerations
The “ECHO” Diagnostic Safety Function
The LDP1WC-47 features a proprietary Electronic Circuit Health Output (ECHO) loop. Because this switch uses dedicated discrete analog elements rather than a microprocessor, it avoids software lockups. The internal self-monitoring circuitry actively monitors for internal board failures or loss of incoming 24 V DC infrastructure power, providing a fail-safe interlocking alert to the facility alarm monitoring system if component failure occurs.
Maintenance Mode Avoidance of False Trips
A persistent issue in cleanroom facility maintenance is the accidental tripping of low-pressure safety interlocks during routine ventilation balancing or exhaust system maintenance. By jumping or closing terminal connections 3 and 4 (via an external keyed physical switch or system software relay), operators trigger the “Maintenance Mode”. This safely expands the operational high/low trip boundaries to 5% and 95% of the total 20” WC envelope, preventing false system shutdowns while keeping basic pressure detection active. Removing the jumper instantly drops the configuration back to the original narrow process setpoints.
Transient Pulse Filtering
The onboard adjustable time delay serves as a hardware damper for pneumatic transient pulses. For example, when doors close or damper positions cycle, air pressure spikes briefly. If a pressure excursion outside the set limits occurs, the faceplate status LED instantly flips from green to red. However, the dry contact relay will hold its operational state until the selected time delay window (e.g., 10 seconds) expires. If pressure self-corrects within that window, the timer clears down to zero without disrupting the ventilation interlock loop.
Frequently Asked Questions
What happens to the relay contact output when a genuine pressure threshold is breached?
When an alarm threshold is sustained past the chosen time delay, the electromechanical relay contacts latch open, the process display flashes the monitored pressure once per second, and the LED turns solid red. Because this unit utilizes a latching mechanism for safety interlock integrity, human intervention is mandatory; you must clear the underlying ventilation fault and manually press the physical reset button on the faceplate to clear the alarm state and close the dry contacts.
Can I run corrosive process exhaust gases directly into the sensor ports of this unit?
No. The base LDP1WC-47 model is built with internal sensors meant for clean, dry air or standard non-conductive inert carrier gases. If your application directly extracts toxic or corrosive acid vapors (such as tool exhaust containing halogen compounds), verify with the OEM if you require the specialized Corrosive Media variant which incorporates stainless steel wetted components.
Does this unit provide a continuous analog tracking signal for SCADA data logging?
While some EchoLine monitors have optional 4-20 mA or 0-10 V DC tracking loops, you must verify the specific model dash code with the exact wiring diagram on the back of the polycarbonate housing. If your unit does not have the analog logging pins, it operates strictly as a dual-point threshold switch using the SPDT output.
