Instruction Manual

HMP230 SERIES
M210225en-B User's Guide
23
Power supply 24 VDC
24 VAC (see page 23)
with power supply module 115/230 VAC
Output signals 0...20 mA, 4...20 mA
0...1 V, 0...5 V, 0...10 V
Power supply ground (-) is connected to the housing with parallel connection
of 15 nF capacitor and 300 k resistor.
See Appendix 2 on how to connect the power supply module to the
transmitter.
3.4.1. Connection to a 24 VAC supply
The HMP230 transmitters can also be connected to a 24 VAC supply without
an external rectifier. However, when more than one transmitter is connected to
one 24 VAC transformer, a common loop is formed and there is an increased
risk of a short-circuit. To avoid this, always use separate floating supply for
each transmitter (see Figure 21 A). However, if several transmitters have to
share one transformer, the phase () must always be connected to + connector
in each transmitter (see Figure 21 B).
24 VAC
HMP230 transmitter
HMP230 transmitter
Controller
shared
common
24 VAC
24 VAC
HMP230 transmitter
HMP230 transmitter
Controller
B) COMMON LOOP FORMED -
NOT RECOMMENDED!
A) NO COMMON LOOP FORMED - RECOMMENDED
supply
voltage
signal
output
supply
voltage
signal
output
supply
voltage
supply
voltage
signal
output
signal
output
line
Figure 21 Connecting the transmitters to a 24 VAC supply