VorTek Pro-T, Instruction Manual

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Series M22/M23/M24 Instruction Manual Chapter 2 Installation
M-000-00010 2-33
Alarm Output Connections
One alarm output (Alarm 1) is included on the standard Pro-V ™ Flow
Meter. Two or more alarms (Alarm 2 and Alarm 3) are included on the
optional communication board. The alarm output requires a separate 5 to
36 VDC power supply. The alarm output optical relay is a normally-open
single-pole relay. The relay can conduct a current up to 40 mA. It is iso-
lated from the meter electronics and power supply. When the alarm relay
is closed, the current draw will be constant. Make sure to size R
load
appro-
priately.
There are three connection options for the alarm output
– the first with a sep-
arate power supply (Figure 2-39), the second using the flow meter power
supply (Figure 2-40)(DC powered units only) and the third with the meter
provided power supply (Figure 2-41)(AC powered units only). Use the first
option with a separate power supply (5 to 36 VDC) if a specific voltage is
needed for the alarm output. Use the second configuration if the voltage at
the flow meter power supply is an acceptable driver voltage for the load
connected. (Take into account that the current used by the alarm load comes
from the meter’s power supply ). Use the third if you have an AC powered
unit only. In any case, the voltage of the alarm output is the same as the
voltage supplied to the circuit.
The alarm output is used for transmitting high or low process conditions
as defined in the alarm settings (see page 3-9).
AC or DC powered meters
ALARM
ALARM
Figure 2-39. Isolated Alarm Output Using External Power Supply
DC units only
Figure 2-40. Non-Isolated Alarm Output Using Internal Power Supply