Connecting WMT700 cables - WMT700

WMT700 Series User Guide

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User guide
WARNING Make sure that you prepare or connect only de-energized wires.
WARNING A long cable between units (sensors, transmitters, power supplies, and displays) can cause a lethal lightning-induced current surge. Always ground the enclosure to a suitable grounded location with a short, low-resistance cable.
CAUTION Make sure that the cable is properly attached to the mast or cross arm before starting the installation. Otherwise, it may slip and fall down during the installation procedure.
CAUTION To avoid strain on the connector, make sure you connect the cable properly. Too much strain may cause the cable to fall off, damage the cable or connector, or make the cable or connector susceptible to water leakage.

WMT700 cables have an easy-to-use cable connector. Tighten the connector by hand. Do not use tools.

If you have a cable tightening tool supplied by Vaisala in the past, do not use it with the current cable connector.

4-mm Allen key
The recommended minimum bending radius for the cable is 80 mm (3.15 in).

When installing WMT700, route the cable according to the mounting option. When mounting on a mast, you can route the cable either outside or inside the mast. Cable routing depends on the mast type and other equipment, such as air terminals, installed on the mast.

There are 3 WMT700 cable types:

  • The hybrid cable designed for the fully heated WMT700. You can use it with all versions.
  • The standard cable for non-heated, transducer-heated, and transducer-and-arm-heated WMT700.
  • The RS‑485 cable for RS‑485 connections only. You can use it for non-heated, transducer-heated, and transducer-and-arm-heated WMT700.
Table 1. WMT700 cable types
Cable type Fully-heated WMT700 Transducer-and-arm-heated WMT700 Transducer-heated WMT700 Non-heated WMT700
Hybrid cable
Standard cable
RS‑485 cable
  1. Loosen the M5 screws (3 pcs) with a 4‑mm Allen key and rotate the connector cover to remove it.
  2. To attach the connector, guide it to the connector slot.
  3. Align the male and female connectors.
  4. To tighten the connector, turn the locking ring.
    CAUTION Turning the connector body may break the connector.
  5. Reattach the connector cover and tighten the M5 screws (3 pcs) with a 4-mm Allen key. Tightening torque 3 Nm.

    To verify that the cable is tight, wiggle the cable and make sure the locking ring is tight. Wiggling makes the connector tightening sleeve loose. Tighten the cable again. Repeat until firmly tight.

    Make sure that you tighten the connector properly to avoid water leakage and damage to the sensor. Failure to tighten the connector properly voids the warranty.
  6. Connect the wires.