FOXBORO RH914SV – Hermetically Sealed Interposing Relay for DCS/PLC Marshalling and Isolation

The FOXBORO RH914SV is a rugged, hermetically sealed relay typically used as an interposing element between DCS/PLC logic and field devices. From my experience, this RH9xx family relay shows up in Foxboro I/A Series and legacy marshalling panels where reliable dry-contact switching and electrical isolation really matter—solenoid valves, annunciation, permissives, and general purpose on/off control. You might notice that maintenance teams favor this series because it drops straight into standard relay sockets and keeps signal wiring tidy.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days
• Delivery time: 1 week for in‑stock items; no more than one month at the latest
• Payment: 50% advance payment; full payment before delivery
• Express delivery: FedEx, UPS, DHL

Key Features

• Hermetically sealed construction – Helps protect contacts from dust, moisture, and contaminants; in many cases it extends service life in control cabinets.
• Interposing relay role – Provides galvanic isolation between low‑level control outputs and field loads like solenoids, lamps, and contactor coils.
• Socket‑mount, serviceable design – Plug‑in base makes replacements quick; one thing I appreciate is how it minimizes instrument downtime during turnarounds.
• Stable coil behavior – The RH9xx family is known for consistent pickup/dropout; typically prevents nuisance chatter in mixed AC/DC panels.
• Multi‑pole dry contacts – Suitable for permissive logic, parallel indication, or splitting one control signal to multiple circuits (within rating).
• Legacy system compatibility – Commonly found in Foxboro marshalling and logic bays; a practical drop‑in when you’re keeping an installed base healthy.

Technical Specifications

Application Fields

This relay is used across process industries where Foxboro systems are installed. Typical scenarios include:

• Interposing between DCS/PLC outputs and solenoid valves on skids or manifold blocks
• Alarm/annunciator contact driving and lamp/sounder isolation
• Permissive and trip logic in compressor, boiler, or turbine control panels
• Contact multiplication for parallel indication (MCC signals, valve limit switches)
• Retrofit maintenance for legacy Foxboro marshalling bays to keep wiring unchanged

Advantages & Value

• Reliability – Hermetic sealing and robust coil design reduce nuisance failures in mixed‑voltage cabinets.
• Compatibility – Fits typical Foxboro relay sockets; no re‑engineering of field terminations in most cases.
• Cost control – A simple relay swap often avoids redesigning I/O cards or marshalling strips.
• Support – We help confirm coil voltage and contact form before shipment to prevent site mismatches.

Installation & Maintenance

• Cabinet environment – Install in ventilated control panels; avoid dripping moisture and corrosive gas exposure.
• Wiring – Verify coil voltage and polarity (for DC). Use appropriate suppression across inductive loads (RC snubber or diode) to minimize contact arcing.
• Mounting – Plug into the correct socket base; use a retaining clip where vibration is present. Keep conductors neatly dressed to reduce strain.
• Routine checks – Periodically exercise the relay, check contact resistance, and inspect for heat discoloration at terminals.
• Lifecycle – For high‑cycle applications, plan contact wear monitoring and keep spares on hand; in many cases, a swap takes only minutes.

Quality & Certifications

• Certifications – Variants in this family commonly carry CE marking and, in many cases, UL recognition; RoHS compliance may depend on vintage.
• Warranty – 365‑day warranty from delivery.

Helpful Accessories (Optional)

• Plug‑in relay socket (matching pin pattern), DIN‑rail adapter (35 mm), and a spring retaining clip for vibration‑prone panels.
• Coil suppression modules (RC snubber for AC loads, diode for DC) to extend contact life.
• Test socket with lever for maintenance teams who routinely prove out I/O.

If you’d like, share your target coil voltage and contact form; we’ll verify the exact RH914SV variant compatibility before shipping.