CAUTION With the installation of the equipment in Zone 0 Group II area it has to be ensured that sparks due to impact or friction do not occur. |
Wiring requirements
- Only use cables and cable glands suitable for +80 °C (+176 °F)
- The cable glands and cables used for
wiring the device must not impair the Ex protection.
- Unused lead-throughs must be sealed using Ex compliant plugs.
- Select a strain relief option that suits the application (either use cable glands that include strain relief or install separate clamps: see IEC 60079-14).
CAUTION Connect only de-energized wires. Never switch on the power supply input before completing the wiring and closing the transmitter body. |
Intrinsic safety
The overvoltage category of HMT370EX transmitters is I (non-mains equipment), and ambient pollution degree is 4, as specified in IEC 60664-1. For intrinsically safe input parameters, see Table 1.
Parameter | Value | Associated apparatus entity parameters |
---|---|---|
Ui | 28 VDC | Uo ≤ Ui |
Ii | 100 mA | Io ≤ Ii |
Pi | 700 mW | Po ≤ Pi |
Ci | 12.1 nF | Co ≥ Ci + Ccable |
Li | 16 µH | Lo ≥ Li+ Lcable |
Using analog output test points
- 1
- Multimeter test points for analog output channels 1 and 2
- 2
- Service port for PC connection
CAUTION
The transmitter body enclosure must not be opened in an explosion hazardous area, unless a safe work permit has been issued in accordance with the standard IEC 60079-14. Either remove the transmitter from the hazardous area before opening the enclosure, or ensure that an IEC 60079-14 compliant safe work procedure has been implemented in the hazardous area. |
Using the service port
The service port (see Figure 1) must only be used in a safe area. Either remove the transmitter from the hazardous area or ensure that a safe work procedure has been implemented in the hazardous area. Only use the Vaisala accessory PC connection cable with the service port.
Maintenance
The probe (includes probe body and head) can be detached and replaced by the user. The probe head filter (see Figure 1) is also user-replaceable. For other maintenance requirements, contact Vaisala.
CAUTION The probe can be detached and changed when HMT370EX is powered. Any other live maintenance, including changing the probe head filter, is not allowed. |