ABB SPASO11 – Reliable Protection Relay for Industrial Power Systems

If you’re managing medium-voltage switchgear or working on substation automation, the ABB SPASO11 is one of those compact yet dependable protection relays that tends to fly under the radar—until you actually need something that just works. From my experience, it’s typically found in older but still-operational ABB REF 501 or REL 5xx systems, where it serves as an auxiliary trip relay rather than a full-line digital protector.

You might notice that it doesn’t have communication ports or programmable logic like modern IEDs. That’s by design. It seems to be built for simplicity—handling tripping commands from primary relays and ensuring fast actuation of circuit breakers when fault signals come through.

Key Features

• Dedicated trip relay function: Amplifies and isolates trip signals from main protection units to drive high-current breaker coils reliably.
• Electromechanical output contacts: Typically rated for 250V AC/DC and up to 5A, which handles most legacy breaker trip circuits without needing external contactors.
• Galvanic isolation: Input-to-output isolation helps prevent noise interference and protects upstream devices in noisy industrial environments.
• Fail-safe operation: In most cases, if power is lost or the unit fails, it defaults to a de-energized state—critical for safe shutdown behavior.
• Compact DIN rail mounting: Fits easily into standard control cabinets alongside other ABB protection modules.

Technical Specifications

Parameter	Specification
Brand / Model	ABB / SPASO11
HS Code	85371090
Power Requirements	24–250 V DC or AC (wide-range supply input)
Dimensions & Weight	Approx. 70 mm (W) × 100 mm (H) × 60 mm (D), ~350 g
Operating Temperature	-25°C to +55°C
Signal Input Type	Binary input (trip command via isolated dry contact or powered signal)
Output Type	1–2 changeover relay contacts (typically CO type, 5A switching capacity)
Communication Interfaces	None – purely electromechanical logic execution
Installation Method	Top-hat DIN rail (35 mm)

Application Fields

The SPASO11 shows up most often in retrofit projects involving aging ABB-based protection panels—especially in utilities, mining operations, and industrial plants with existing REL/REF series relays. It’s not a smart device, but in many cases, that’s exactly what makes it valuable: no firmware bugs, no configuration tools needed, and minimal points of failure.

One thing I appreciate is how frequently this module appears in backup generator control schemes or transformer protection cubicles where reliability trumps connectivity. It can also serve as a re-trip latch or alarm repeater in simple interlocking circuits.

Advantages & Value

While newer multifunction relays offer more features, the SPASO11 brings real value in compatibility and uptime. If you’re maintaining legacy infrastructure, sourcing an exact replacement matters—and this part integrates seamlessly without requiring panel modifications.

Procurement-wise, it’s relatively low-cost compared to full IEDs, and since it has no software, there’s zero licensing overhead. Technical support is straightforward too—most electricians understand relay logic, so troubleshooting rarely needs specialist intervention.

Installation & Maintenance

Install in a clean, dry enclosure meeting IP54 or better. Make sure the DIN rail is securely mounted and avoid placing near heat-generating components like transformers or frequency drives. Ventilation should allow free airflow around the unit, especially if operating near upper temperature limits.

Wiring should use stranded copper conductors with ferrules, sized appropriately for 5A loads. Double-check polarity on DC-powered versions—reverse connection won’t always destroy it immediately, but may reduce coil life over time.

Routine maintenance includes visual inspection for discoloration or arcing marks, checking terminal tightness annually, and verifying contact operation every 18–24 months. No calibration is possible or required—it either works or doesn’t, which simplifies field diagnostics.

Quality & Certifications

The ABB SPASO11 complies with major international standards including:
• CE Marking (EMC and Low Voltage Directives)
• UL Recognized Component (under file number E103198)
• RoHS compliant
• Designed per IEC 60255-1 (insulation and dielectric tests)

Units shipped from inventory include a 365-day warranty against manufacturing defects. Given its passive nature, failures are rare—but when they occur, it’s usually due to sustained overvoltage or environmental stress like moisture ingress.

Our Order Placement Process and Guarantees

Delivery Time: 1 week for in-stock units. For out-of-stock or batch-dependent items, delivery takes no more than one month.
Payment Method: 50% advance payment, balance due before shipment.
Express Delivery: Shipped via FedEx, UPS, or DHL—your choice at checkout.
All units are tested prior to dispatch and packaged to withstand long-distance transit.