Description
ABB DSSR122 48990001-NK Power Supply Unit
Product Introduction
The ABB DSSR122 48990001-NK is a dedicated DC-input/DC-output power supply unit used in ABB Advant Master process-control equipment. ABB identifies the unit as DSSR 122 and describes its function as a power supply with a 24 VDC input and regulated 5 VDC output rated at 40 A. The same product record identifies EXC48990001-NK as the exchange number and specifies a 20 A spare fuse under part number 5672827-20.
In practical system terms, ABB DSSR122 48990001-NK is a rack-level power component rather than an I/O, CPU, or communications module. It converts the incoming DC supply into the regulated low-voltage rail required by the associated control-system electronics. The 40 A output corresponds to approximately 200 W at the stated 5 V output, so this unit should be evaluated as a substantial system power source rather than as a small auxiliary supply. ABB product records also associate the DSSR 122 with Advant control-system and S100 I/O power-supply applications.
For maintenance work, exact identification matters. The ABB DSSR122 48990001-NK is an older Advant-family component, and replacement should not be based only on the nominal 24 V input. The output voltage, 40 A capacity, physical envelope, rack connection, fuse arrangement, and system compatibility all need to match. The available ABB-derived documentation provides reliable core electrical data, but detailed values such as efficiency, ripple, thermal derating, and protection thresholds should be confirmed from the equipment documentation or the nameplate before being used for engineering calculations.
Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | DSSR 122 |
| ABB Product ID | 48990001-NK |
| Exchange Number | EXC48990001-NK |
| Manufacturer | ABB |
| Product Type | DC/DC Power Supply Unit |
| Input Voltage | 24 VDC |
| Output Voltage | 5 VDC regulated |
| Output Current | 40 A |
| Nominal Output Power | Approx. 200 W |
| Communication Protocol | None |
| Interface Type | Dedicated power/rack connections |
| Dimensions | 238.5 × 162 × 72 mm |
| Weight | 2.35 kg |
| Spare Fuse | 20 A, P/N 5672827-20 |
| Installation | System/rack installation |
| Protection Rating | Not verified in ABB product record |
| Operating Temperature | Not verified in ABB product record |
| Output Accuracy | Not specified in available ABB product record |
| Associated System Family | ABB Advant Master / related Advant control-system applications |
| RoHS Status | ABB documentation notes exemption under specified RoHS Article 2(4) provisions |
The core electrical specifications above are taken from ABB-derived product documentation.
DSSR122 48990001-NK
Main Features and Engineering Considerations
1. High-current 5 VDC output
The defining characteristic of the DSSR 122 is its 5 VDC regulated output at 40 A. At the nominal rating, this represents roughly 200 W of DC output capacity. This is appropriate for supplying a group of rack electronics rather than a single low-power instrument.
2. 24 VDC input architecture
The unit is specifically documented for 24 VDC input. Some secondary listings publish an 18–30 VDC input range, but that range is not established in the ABB product record reviewed here. For a replacement specification, 24 VDC should therefore be treated as the verified nominal input rather than assuming an allowable operating range.
3. Advant-system application
ABB categorizes DSSR 122 under its Advant control-system power products. Product documentation also associates the unit with Advant Master process-control applications and S100 I/O power-supply configurations.
That makes system compatibility more important than simply matching voltage. The rack/backplane interface and the expected 5 V power distribution must be confirmed before installing another supply.
4. Dedicated power function
There is no indication that DSSR 122 performs control logic, signal conversion, network communication, or I/O processing. It is a power-conversion assembly. Troubleshooting should therefore focus on the input supply, output rail, fuse, rack connections, and downstream loading rather than treating the module as an intelligent controller.
5. Spare-fuse identification
ABB specifies a 20 A spare fuse, part number 5672827-20. If a DSSR 122 is found with a failed fuse, replacing the fuse without checking the reason for the overcurrent is poor maintenance practice. A downstream short or damaged rack assembly can immediately cause a replacement fuse to fail.
6. Physical fit
The documented dimensions are 238.5 mm deep × 162 mm wide × 72 mm high, with a listed weight of approximately 2.35 kg. These dimensions should be checked against the available rack space and original mounting arrangement before procurement.
Application Scenarios
ABB Advant Master Process Control
The primary documented context is ABB’s Advant Master process-control architecture, where the DSSR 122 functions as a dedicated power-supply unit.
Advant Controller and Rack Power
ABB product categorization associates DSSR 122 with Advant controller and power-supply applications. The unit can therefore be encountered in legacy control-system racks where regulated low-voltage power is distributed to system electronics.
S100 I/O Systems
ABB’s product categorization also places DSSR 122 within S100 I/O power-supply applications. When maintaining such equipment, the exact rack configuration should be checked before assuming that every DSSR-series power unit is interchangeable.
Engineer’s Guide: Field Pitfalls
Pitfall 1 — Treating it as a generic 24 V power supply
The 24 V figure is the input, not the output. DSSR 122 converts 24 VDC to a regulated 5 VDC / 40 A output.
Pitfall 2 — Assuming every 24 VDC-to-5 VDC converter is compatible
The electrical conversion ratio alone does not establish compatibility. Rack interface, connector arrangement, output distribution, mechanical dimensions, and system loading must be checked.
Pitfall 3 — Replacing a blown 20 A fuse without investigating the load
ABB specifies a 20 A spare fuse. A repeatedly blown fuse should trigger an investigation of the power supply and downstream rack circuits.
Pitfall 4 — Confusing DSSR 122 with an intelligent module
This is a power-supply unit. It does not replace a controller, communication module, or I/O module.
Pitfall 5 — Using undocumented environmental specifications
Several secondary listings publish temperature, efficiency, IP rating, and protection claims that are not present in the ABB product record reviewed here. Those values should not be copied into a critical engineering specification without verification.
Pitfall 6 — Ignoring legacy-system status
DSSR 122 belongs to an older ABB control-system product family. For an operating plant, keep the exact 48990001-NK identifier, hardware markings, system type, rack position, and existing wiring information in the procurement record.
Frequently Asked Questions
What is ABB DSSR122 48990001-NK?
It is an ABB DSSR 122 power supply unit, product ID 48990001-NK, designed for DC-input/DC-output operation in ABB Advant control-system applications.
What is the input voltage?
The documented input is 24 VDC.
What is the output voltage?
The output is 5 VDC regulated.
How much current can it supply?
The documented output rating is 40 A.
What is the approximate output power?
At the stated nominal rating, 5 V × 40 A equals approximately 200 W.
Is DSSR122 an ABB DCS I/O module?
No. It is a power supply unit used within ABB control-system infrastructure.
What is the exchange number?
ABB documentation identifies EXC48990001-NK as the exchange number.
What fuse is specified?
ABB lists a 20 A spare fuse, part number 5672827-20.
What are the physical dimensions?
The documented dimensions are approximately 238.5 mm × 162 mm × 72 mm, with a product weight of about 2.35 kg.
Procurement Note
For a maintenance purchase, specify the part as ABB DSSR 122 / 48990001-NK and, where applicable, retain the exchange number EXC48990001-NK. Confirm the unit’s 24 VDC input and 5 VDC / 40 A output against the original installation.
For used or refurbished stock, request photographs of the actual nameplate and connector side, not only a catalog photograph. Check the hardware revision, connector condition, fuse area, signs of overheating, corrosion, and capacitor aging. A bench test should verify the 5 VDC output under an appropriate load before the unit is returned to a live Advant rack.
Do not approve a substitute solely because it is advertised as a 24 VDC-to-5 VDC, 40 A converter. The rack interface and system-specific electrical behavior are part of the replacement decision.
