1606-XLRED40 Allen-Bradley Redundancy Module: Legacy Diode Decoupling for Critical DC Buses
The 1606-XLRED40 is an older-generation Allen-Bradley redundancy module from the Bulletin 1606-XL family. It is a passive diode decoupling unit. It lets two or more 24 V DC supplies share a load in 1+1 or N+1 redundancy. A built-in decoupling diode isolates the branches. A ready relay contact reports module status. Screw terminals keep wiring simple. There is no communication interface and no power conversion. The unit drops about 0.6 V from input to output. Efficiency stays above 97%. This is a practical part for keeping legacy control systems running.
Core Electrical and Mechanical Data
- Input: DC 24 V nominal, max rated 35 V, short-term 45 V
- Output: DC 24 V nominal, Vin→Vout drop typical 0.6 V
- Current: 40 A nominal, 50 A max rated, per input and output
- Efficiency: >97% passive diode design
- Mounting: DIN rail, open-frame, IP20
- Dimensions (H×W×D): 124 × 48 × 117 mm
- Weight: 646 g
- Terminals: screw type, per 1606-AP037
Environment and Operating Limits
- Operating temperature: -10…+70 °C
- Storage temperature: -25…+85 °C
- Humidity: not published for legacy XL series
- Protection: IP20, cabinet installation required
- No derating data published beyond the temperature range
Lifecycle and Compatibility
- Official status: Discontinued as of October 30, 2017
- Direct replacement: 1606-XLSRED40
- Fits existing Bulletin 1606-XL DIN rail layouts
- Works with 24 V DC supplies in 1+1 or N+1 schemes
- No protocol or bus interface to configure
Where This Module Fits Best
- 24 V DC control buses needing supply redundancy
- Legacy machines with paired power supplies
- Process lines where a single supply failure must not stop the load
- Retrofit projects replacing failed decoupling diodes
- Panel builds that still follow the original 1606-XL drawing set
Certifications and Shipment Terms
- Approvals: UL 60950-1, cUL, CE marked
- Warranty: 12 months from Oiltech Controls
- Dispatch window: 24-28 hours after order confirmation
- Carriers: FedEx, UPS, DHL
Oiltech Controls’s Insight
- Passive diode modules rarely fail from wear. Most returns come from overloaded terminals or reversed polarity.
- Check the 0.6 V drop against your load tolerance before fitting a replacement.
- Confirm the ready relay contact wiring matches the original panel drawing.
- Keep a spare module on site. The part is discontinued and lead times can stretch.
- We test each unit for forward drop and relay function before dispatch.
Why Buy From Oiltech Controls?
- More than 15 years sourcing industrial automation spares
- Shipping to customers worldwide, with tracking on every parcel
- Surplus and refurbished units, each tested before listing
- Every order carries a 12-month warranty
- Technical check on voltage, current and contacts before shipment
- Ongoing supply for obsolete control systems
FAQ
Q: Can I use the 1606-XLRED40 with 12 V supplies?
A: No. The module is rated for 24 V DC nominal. The maximum rated input is 35 V, with short-term 45 V. Stay within that window.
Q: Is the 0.6 V drop a problem for long cable runs?
A: It can be. Add the drop to your cable losses. Keep total voltage at the load above its minimum. Many engineers set the upstream supply slightly higher to compensate.
Q: What does the ready relay contact actually signal?
A: It reports module readiness, not individual supply health. For per-supply diagnostics, monitor each power supply’s own status output.
Q: How do I size the module for N+1?
A: Use the 40 A nominal figure per input and output. The 50 A max rated value is a short-term limit, not a continuous rating. Size for the full load current with one branch out.
Q: Is the 1606-XLSRED40 a drop-in swap?
A: Rockwell lists it as the direct replacement. Still check terminal layout and relay contact pinout against your panel drawing before ordering.
Contact Information
Inquiries: info@oiltechcontrols.com
Phone / WhatsApp: +86 158 8020 0923
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