The Dell 1KXFV is a 550 W reverse-airflow AC power supply for the PowerSwitch S4048T-ON and the S4100 series, drawing air in at the port face and exhausting it at the PSU face. It is a hot-swappable field-replaceable unit and it is interchangeable with Dell part numbers 3WVHP and 664CN.
Why the airflow direction is on the label
These switches are built in two thermal variants and the power supply is half of that decision. A reverse-airflow chassis exhausts at the power-supply end, which is what you want when the switch is mounted ports-forward in a cold-aisle-facing rack - it keeps the exhaust in the hot aisle with the servers. Dell writes this as PSU-IO in the part description; the normal-airflow supply is marked IO-PSU.
Both supplies in a chassis must pull the same direction, and they must match the fan modules. A switch running one reverse-airflow supply and one normal-airflow supply has two opposing air paths inside a single 1U enclosure. It will not fail immediately - it will just run hotter than it should, permanently.
Redundancy
The S4048T-ON and S4100 platforms take two supplies. Running both gives you N+1: a supply can fail, or be swapped, without the switch going down. Running one is supported but leaves a single point of failure on a device that an entire rack depends on. If you are buying a replacement for a failed unit, this is the moment to check whether the second bay was ever populated.
Which switches take it
S4048T-ON, and the S4100 series: S4112F-ON, S4112T-ON, S4128F-ON, S4128T-ON, S4148F-ON, S4148T-ON, S4148U-ON and S4148FE-ON.
Condition
Refurbished, tested and covered with warranty.
Related models
Specifications
| Output | 550 W AC |
|---|---|
| Airflow direction | Reverse airflow (port-to-PSU, [PSU-IO]) |
| Platform | Dell PowerSwitch S4048T-ON and S4100 Series |
| Redundancy | Switches take two supplies; both must share the same airflow direction |
| Serviceability | Hot-swappable field-replaceable unit |
| Interchangeable Dell part numbers | 3WVHP, 664CN |
| Shipping weight | 0.5 lbs |
