The primary AC power is connected to a separate terminal strip 31/32/33 marked POWER in the lower right-hand corner of the motherboard. The 3 terminals are marked 31/L, 32/N and 33/ (protective earth). The power terminal 33 is directly connected to the exposed metal parts of the indicating transmitter DTR. Wiring to the terminals must be of min. 1.5 mm2. The fuse voltage should be 250 V, max. size 10 A and fuse speed slow. Make sure that the protective fuse in the building system complies with local requirements.
If you use an AC power terminal, Vaisala recommends that you install an external power switch. The ratings of the external power switch are 10 A and 250 V. Make sure that you mount the external power switch close to the indicating transmitter and that it is easily reachable. Make sure that you mark the external power switch as a disconnecting device.
The following figure shows the recommended external power switch, spare part PR‑10900.