Siemens 6ES5988-3NB11 Fan Replacement

The Siemens 6ES5988-3NB11 provides a direct replacement cooling fan for S5 expansion racks. This fan kit measures 120 mm in width and 120 mm in height. It has a depth of 38 mm, so it fits standard rack cutouts easily. The unit weighs 0.42 kg, making installation quick and straightforward.

Fan Specifications and Airflow Performance

This replacement fan moves air at a rate of 65 cubic feet per minute. The Siemens 6ES5988-3NB11 spins at 2800 revolutions per minute for consistent cooling. It uses dual ball bearings for extended mechanical service life. The fan achieves 50,000 operating hours at room temperature conditions. A removable dust filter prevents debris from entering the rack interior.

Power Requirements and Electrical Interface

You will find a pre-wired 2-pin connector on the fan’s output cable. The Siemens 6ES5988-3NB11 accepts 24V DC with a tolerance of ±10 percent. The fan draws only 180 mA under normal operating conditions. Therefore, total power consumption stays at 4.32 watts during continuous use. The assembly stores no electrical energy internally for safety reasons.

Installation and Compatibility Details

This kit includes four mounting screws and a new foam filter pad. The Siemens 6ES5988-3NB11 fits directly into S5-115U, 135U, and 155U racks. You do not need any special tools or adapters for installation. The fan connector mates with the existing power header inside the rack. A polarity protection diode prevents damage from incorrect wiring.

Environmental Tolerance and Maintenance

The Siemens 6ES5988-3NB11 operates reliably from -10°C to 55°C ambient temperature. It tolerates humidity levels up to 90 percent without any condensation issues. The front grille includes a finger guard for technician safety during operation. You should clean the foam filter every three months for optimal airflow. The fan automatically restarts after a power interruption without manual intervention.

Below is a complete summary of its technical specifications.

Parameter	Value
Dimensions (W x H x D)	120 mm x 120 mm x 38 mm
Weight	0.42 kg
Airflow Rate	65 CFM
Fan Speed	2800 RPM
Bearing Type	Dual ball
Rated Life	50,000 hours
Operating Voltage	24V DC ±10%
Current Draw	180 mA
Power Consumption	4.32 W
Connector Type	2-pin pre-wired
Filter Type	Removable foam
Mounting Screws	4 included
Polarity Protection	Yes
Operating Temperature	-10°C to 55°C
Humidity Tolerance	90% non-condensing

The Siemens 6ES5988-3NB11 replaces failed fans in S5 rack power supplies directly. You do not need any special adapters or additional wiring harnesses. This kit also includes all necessary hardware for a complete replacement. Consequently, it restores proper cooling and prevents overheating of S5 modules.