Description
Product Introduction
The Allen-Bradley 1336-SN-SP10A is an OEM snubber board sub-assembly designed for legacy 1336 series variable frequency drives (VFDs). Installed directly within the drive’s internal power structure, it damps inductive switching spikes generated when high-power IGBTs chop the high-voltage DC bus.
Without a properly functioning snubber circuit, fast voltage transients will punch through the gate insulation of expensive power modules during rapid deceleration or heavy motor loads. This board uses heavy-duty energy-absorption capacitors and power resistors to clamp those voltage spikes, keeping your drive operating cleanly without sudden hardware failure.
Key Technical Specifications
| Parameter | Specification |
| Manufacturer | Allen-Bradley / Rockwell Automation |
| Part Number | 1336-SN-SP10A |
| Product Line | 1336 PLUS, 1336 PLUS II, 1336 FORCE Drives |
| Component Type | Snubber PCB Assembly |
| Function | Transient Voltage Clamping & dV/dt Suppression |
| DC Bus Voltage Rating | Compatible with 460V AC / 575V AC Drive Frames |
| Mounting | Direct Chassis / Power Module Standoff Mount |
| Operating Temperature | 0°C to 50°C (32°F to 122°F) |
| Enclosure Rating | Open PCB (Internal VFD Chassis Mount) |
Application Scenarios & The “Trench” Experience
A critical 100 HP exhaust fan drive on a glass furnace line faulted out with a persistent overvoltage trip during high-wind load changes. The root cause wasn’t the utility power—it was a cracked resistor element on the aging snubber board that could no longer bleed off transient voltage surges from motor regeneration. Swapping in a fresh 1336-SN-SP10A snubber card restored full damping capability, preventing a $15,000 drive replacement and avoiding a full plant shutdown.
- Centrifugal Pump & Fan Drives – Absorbs regenerative energy spikes during rapid deceleration cycles.
- Extruders & Heavy Mixers – Protects inverter power stages against severe line-side voltage transients.
- Overhead Crane Hoists – Clamps high-voltage inductive kickback generated during mechanical brake actuation.
- Legacy VFD Fleet Maintenance – Keeps legacy Allen-Bradley 1336 drive infrastructure running without expensive control retrofits.
Transparency SOP: Quality Assurance & Testing
We don’t just ship boxes; we test industrial power electronics on actual 1336 drive chassis:
- Inbound Visual & Component Audit: Inspect power resistors, film capacitors, and trace metalization for heat discoloration, cracking, or electrolyte leakage.
- Capacitance & ESR Testing: Verify all energy-storage capacitors using an LCR meter to ensure low Equivalent Series Resistance (ESR) and full microfarad rating.
- High-Voltage Insulation Check: Perform insulation resistance (Megger) testing across isolated trace networks to confirm zero arc-over paths.
- Live Drive Bus Integration Test: Mount the board into an active 1336 test frame under load to verify voltage clamping behavior.
- ESD Static Packaging: Package the board in heavy-gauge anti-static shielding bags with custom foam cushions for secure transport.
1336-SN-SP10A
1336-SN-SP10A
The Veteran’s Tech Trap Guide
- ⚠️ DANGER: Bleed the DC Bus Capacitors First: Before opening the drive cover to replace this card, measure the DC bus terminals with a multimeter set to DC Volts. Wait until the bus drops below 50V DC. Touch those terminals too soon and you’ll get hit with up to 800 Volts DC—that isn’t a tingle, it’s lethal.
- ❗ Check the Main IGBTs Before Power-Up: If the old snubber board has burned or charred traces, do not just drop this new board in and flip the breaker. A shorted IGBT or blown diode bridge likely caused the snubber to burn. Test all power transistors with a diode check on your meter first.
- ⚠️ Do Not Overtighten Mounting Screws: Screw standoffs on this board route high currents and ground references. Tighten them firmly to secure electrical contact, but do not strip the mounting posts or crack the FR-4 fiberglass substrate.
- ❗ Verify Standoff Insulators: Inspect all nylon and ceramic isolation washers behind the board. If an insulator is missing or brittle, the high-voltage bus can arc straight to the grounded chassis frame, destroying the new board immediately on power-up.
Frequently Asked Questions (FAQ)
Q: Is the 1336-SN-SP10A board hot-swappable while the VFD is powered?
A: Absolute zero. Never attempt to service internal power components while the drive is energized. Disconnect main 3-phase power and lock out the breaker before opening the drive.
Q: Can I use this snubber board across all frame sizes of Allen-Bradley 1336 drives?
A: No. Snubber boards are sized for specific horsepower ratings and frame sizes. Verify that 1336-SN-SP10A matches the exact part number listed in your drive’s renewal parts manual.
Q: Why buy a surplus 1336 board instead of upgrading to a PowerFlex drive?
A: Upgrading to a newer drive platform like PowerFlex requires rewiring, updating PLC communications, and modifying PLC code. Replacing the snubber board gets your existing machine running in 30 minutes for a fraction of the cost.
Q: What type of warranty do you provide on this surplus board?
A: We back this board with a full 12-month replacement warranty from the date of shipment.
Q: Is this unit new surplus or refurbished?
A: This listing is for clean New Surplus stock, fully inspected and bench-tested by our senior drive technicians before shipment.
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