WMT700 has separate power supply inputs for:
- Operating power
- Heating power
The inputs are usually connected to the same 24 V DC power supply unit. Special
applications, such as battery operation or battery backup, may require separate supplies.
The operating power has 1 supply terminal and
1 ground terminal, while the heating power has 2 supply terminals and 2 ground terminals
allowing a higher supply current. All supply ground terminals are internally connected to each
other inside WMT700.
| Make sure that the power supply output
voltage, current, and power specifications including the tolerance match the WMT700
| In a system setup with 2 separate power
supplies, avoid ground potential differences between the supplies. Connect the negative
terminals together if necessary.
| Do not use a DC power supply based on a
chopper circuit that operates at 100 kHz. The ripple in the DC output can distort the
The sensor and the cabling must be
protected with a fuse or a circuit breaker. The maximum sizes of the fuses or circuit
breakers protecting the power lines:
- 13 A with type B, C, or D (IEC/EN
60898-1 or UL 1077) tripping characteristics and specified for at least 40 V DC voltage
operation for heating power supply.
- 1 A with type B (IEC/EN 60898-1)
tripping characteristics and specified for at least 40 V DC voltage operation for
operating power supply.
The circuit breaker can be either 2-pole
(on both positive and negative/ground) or 1-pole (positive wires). You can also replace
the circuit breaker with a cartridge fuse with T (slow acting) tripping