Liquid leak detection in server rooms and technical rooms

Water in a server room or technical room usually comes from the cooling system: chilled-water pipes, room and in-row cooling units, condensate drains and humidifiers, or pipes passing through from the floor above. Leak detection in server rooms is about finding that water before it reaches power distribution and equipment, and telling the right person quickly. This article compares sensing cable and spot probes, explains how to divide a room into zones, covers alarm handling and integration, and describes what the ICP DAS liquid leakage detection products do according to their data sheets.

Sensing cable or spot probe

The sense cable is 6 mm thick, with a fluoropolymer carrier and two 30 AWG sensing wires in a conductive fluoropolymer jacket, rated for 70 °C continuous operation. Two cable types exist:

• CA-LLD-DC100X (1, 3, 5, 10, 30 and 50 m) has snap-in connectors at both ends, so several lengths can be joined in series. Terminated with the CA-LLD-DC100X-TR resistor, it gives cable-break detection: a cut in the leader cable or the sense cable is reported.
• CA-LLD-DC100 (1, 3, 10, 30 and 50 m) has no cable-break detection and cannot be connected in series.

The CA-LLD-EC-L030 leader cable (3 m) connects the sense cable to the module and can be extended with shielded twisted pair, AWG 18 to 14. Leader cable and sense cables together can be up to 500 m. Hold-down clips (ASO-0051 for 180° and ASO-0052 for 90°, 50 per pack) fix the cable to the floor.

Zoning for leak detection in server rooms

Because the module reports that a channel is wet, not where along the cable, the zone layout decides how fast someone finds the water. Practical rules:

• Give each water source its own zone: each cooling unit, each pipe run, each condensate pump.
• Separate areas with different consequences, for example under power distribution and in a corridor.
• Keep zones short enough for one person to inspect quickly.
• Lay the cable where water collects first, such as low points under the raised floor, and loop it around the base of cooling units rather than running one straight line past them.
• Use a probe where a specific point or water level matters, such as a pump sump.

Worked example: one server room, four zones

All four zones connect to one iSN-104-E, which has a separate alarm LED for each channel and reports to the building system over Ethernet. A neighbouring UPS room with a single water pipe gets an iSN-101 whose relay triggers a local siren.

Which ICP DAS products fit

All three alarm on both liquid leaks and cable breaks, accept a probe or a sense cable, and have a sensitivity range of 26 to 580 kΩ set by rotary switch. The iSN-101 relay is a Form A contact rated 2 A at 30 VDC. The iSN-104-E adds access control by ID, password and IP filter. The specified liquid type is water (2 µS/cm), so check other fluids, such as glycol mixtures, with us before relying on them.

Alarm handling and integration

• On site: the buzzer and LEDs tell staff in the room which channel is wet. The mute button silences the buzzer, but the alarm should stay active in the monitoring system until the zone is dry.
• Dry contact: the iSN-101 relay can be wired to a BMS digital input or to the input of an ALM-Horn-RGB siren, which has PoE, Modbus TCP and user-defined RGB LEDs.
• Edge controller: the WISE-5231 reads iSN modules over Modbus RTU or Modbus TCP and can send e-mail, SNMP traps to network monitoring, or MQTT messages, and log each event.
• Direct to SCADA or BMS: the iSN-104-E is polled over Modbus TCP or publishes over MQTT. A BACnet/IP BMS can read it through a GW-2493M gateway.

Treat a cable break as a fault with its own message, because the zone is unprotected until it is repaired, and check in the register map how the module reports each condition. Test every zone with water at commissioning and at regular intervals, and dry the cable afterwards.

Send us a sketch of the room with its water sources, and our technical sales team will propose a zone layout and the matching modules and cables.