Key Technical Specifications
- Input Voltage Range: 18.5 to 36 VDC (accommodates standard 24VDC plant power)
- Regulated Output: 12 VDC at 4.9 A
- System Compatibility: MTL8000 Node Service Carriers & Power Carriers
- Mounting Carrier: 8717-CA-PS Power Carrier (or dual slot on 8711/8712 Node Service Carriers)
- Field Wiring Connection: Top-mounted, two-part detachable connector
- Redundancy Support: Yes, supports secondary power installation for maximum system availability
- Application Area: Hazardous Area (Zone 2 / Div 2) Fieldbus Powering
Product Introduction
I’ve walked through enough chemical plants to know that fieldbus power is usually the first thing to cause a headache when sensors start dropping offline. The MTL 8910-PS-DC was built specifically to solve this by taking your standard 24VDC plant power and regulating it down to a clean 12VDC for your MTL8000 fieldbus carriers. It mounts directly onto the carrier backplane, which eliminates the need for messy external wiring and reduces the chances of a tech accidentally cross-wiring something in a tight junction box.Engineers stick with this power supply because it handles the typical 24VDC fluctuations you find on the factory floor without dropping the bus. With a 4.9A output, it easily powers the carrier and adjacent 4-20mA analog modules. Just be aware that this specific revision is notoriously sensitive to grounding loops, so make sure your carrier backplane is properly bonded to the DIN rail. Other than that, it does exactly what it’s supposed to do.
Quality SOP & Tech Pitfalls
Since this module is discontinued, getting a reliable unit takes extra scrutiny. Here is how we verify them before they ever hit a shipping pallet:
- Visual & Counterfeit Check: We inspect the PCB for cold solder joints, trace corrosion, and verify the OEM silkscreen matches MTL standards.
- Live Load Test: We mount it on an 8717-CA-PS test carrier and pull a continuous 4.5A load at 12VDC for 4 hours to check thermal stability.
- Ripple & Regulation Check: We use a Fluke 115 and an oscilloscope to verify the output ripple stays within spec under load.
- Firmware & Labeling Log: We photograph the exact date code and revision before anti-static sealing.
The Engineer’s Warning: Do not ignore the carrier seating. I once spent six hours troubleshooting a “dead” fieldbus segment, only to find the previous tech hadn’t fully seated the 8910-PS-DC onto the 8717-CA-PS backplane pins. The module looked fine, but the 12V rail was floating. Also, always photograph your DIP switches and jumper settings before pulling the old power supply. Swapping a discontinued part without copying the hardware configuration is a guaranteed way to spend your weekend re-terminating field wiring.
Installation & Configuration Guide
- Pre-Installation: ⚠️ SAFETY FIRST: Lock out and tag out the 24VDC supply. Wait 60 seconds for internal capacitors to discharge. Take a high-resolution photo of the existing wiring and jumper settings.
- Removal: Label all field wires with a sharpie or tag maker. Press the DIN rail release tab firmly with a flathead screwdriver and slide the module straight up. Never pry from the front.
- Installation: Copy the DIP switch and jumper settings from the old module exactly. Align the new 8910-PS-DC with the backplane pins and press down evenly until you hear the mechanical latch click. Reconnect field wires using the two-part detachable connector on top.
- Power-On & Testing: Restore 24VDC power. Check the green “Health” LED on the module. Use a multimeter at the field terminal block to verify a steady 12VDC reading. Download your system config and verify field device communication.
Compatible Replacement Models
| Replacement Option | Compatibility Tier | Notes |
|---|---|---|
| MTL 8920-PS-DC | ✅ Drop-in Replacement | Current OEM equivalent for DC IS power. Verify carrier compatibility. |
| MTL 8913-PS-AC | ⚠️ Software Compatible | AC Input version. Requires 120/240VAC wiring changes and new carrier setup. |
| Third-Party 24V/12V PSU | ❌ Hardware Mod Required | Requires external wiring to carrier. Not recommended for MTL8000 IS segments. |
Frequently Asked Questions (FAQ)
Can I hot-swap this power supply if the system goes down?
No. While the MTL8000 supports redundant power supplies, you should never hot-swap a single primary power supply under load. You risk arcing the backplane pins. Shut down the 24VDC feed first.Why is my 12V output reading low?
Check the input voltage first. If your 24VDC supply is sagging below 18.5VDC due to cable drop or a failing PSU upstream, the 8910-PS-DC will fail to regulate properly. Measure at the module’s input terminals, not just at the panel.Is this module intrinsically safe by itself?
No. The 8910-PS-DC is designed to provide fieldbus power in hazardous areas, but the intrinsic safety of the loop depends on the entire MTL8000 carrier, the IS barriers, and the field device. Always consult the MTL8000 system manual for entity parameter calculations.Can I use this to power standard 24V field devices?
No. This outputs a regulated 12VDC. If you apply it to a 24V transmitter, the device will fault. It is strictly for powering the MTL8000 fieldbus carrier and associated low-voltage interface circuits.The OEM says it’s discontinued. Will you still warranty it?
Yes. We stand behind our surplus and replacement stock with a full 1-year warranty. If it fails under normal operating conditions, we replace it. We know how hard it is to find these, so we test them rigorously before shipping.
