Trimec rt11 - Alarm Outputs; Wiring Requirements

Page 10
3.3 Wiring connections
External DC powering
Powering via 4~20mA loop
Scaled Pulse
Output
Page 11
Alarm Outputs
Wiring requirements
Use multi-core screened twisted pair instrument cable ( 0.25 – 0.5mm
2
) for electrical connection
between the RT and any remote flowmeter or receiving instrument. The screen needs to be earthed
to the signal ground or the receiving instrument, this is to protect the transmitted signal from mutual
inductive interference. Do not
earth the screen at both ends of the cable.
Instrument cabling should not be run in a common conduit or parallel with power and high inductive
load carrying cables, power surges & power line frequencies may induce erroneous noise transients
onto the signal. Run instrument cables in a separate conduit or with other instrument cables.
Position jumper
according to
load type
( NPN or PNP )
0
0
0
0
0
0
PNP
NPN
O/P
8 9
Load
( NPN )
1A max
+
_
6
5
4
3
2
7
8
9
10
11
High flow alarm
Low flow alarm
Scaled pulse output
Remote reset
+ 8~24VDC supply
- 4~20mA output
+ 4~20mA output
Flow input B
Flow input A
-0V Ground
121
-0V Ground + 8~24VDC supply
8 ~ 24 Vdc reg. suppl
y
- +
Load
( PNP )
1A max
+
Position jumper
according to
load type
( NPN or PNP )
0
0
0
0
0
0
PNP
NPN
O/P
8 9
Load
( NPN )
100mA
+
_
6
5
4
3
2
7
8
9
10
11
High flow alarm
Low flow alarm
Scaled pulse output
Remote reset
+ 8~24VDC supply
- 4~20mA output
+ 4~20mA output
Flow input B
Flow input A
-0V Ground
121
-0V Ground + 8~24VDC supply
8 ~ 24 Vdc reg. suppl
y
- +
Load
( PNP )
100mA
+
Low flow
alarm
Position jumper according to load type (NPN or PNP).
NPN = Current sinking, load is between output signal & supply voltage.
PNP = Current sourcing, load is between output signal & ground.
Load
( NPN )
100mA
+
_
6
5
4
3
2
7
8
9
10
11
High flow alarm
Low flow alarm
Scaled pulse output
Remote reset
+ 8~24VDC supply
- 4~20mA output
+ 4~20mA output
Flow input B
Flow input A
-0V Ground
121
-0V Ground + 8~24VDC supply
8 ~ 24 Vdc reg. suppl
y
- +
Load
( PNP )
100mA
+
High flow
alarm
regulated
12~24 Vdc
CAUTION : Do not connect loop
p
ower without a load in series.
- Load +
6
5
4
3
2
7
8
9
10
11
High flow alarm
Low flow alarm
Scaled pulse output
Remote reset
+ 8~24VDC supply
- 4~20mA output
+ 4~20mA output
Flow input B
Flow input A
-0V Ground
121
-0V Ground + 8~24VDC supply
+
_
Note 1: The 4~20mA loop power supply is to be an isolated & regulated dc supply. The integral battery
serves as a back up power source to enable the RT to continue to totalise if the loop power is lost.
Note 2: A separate dc power supply must be used to power active (powered) flow sensors, scaled pulse output
and/or alarm out
p
uts as shown clauses 3.2 and 3.3 res
p
ectfull
y
in this manual.
6
5
4
3
2
7
8
9
10
11
High flow alarm
Low flow alarm
Scaled pulse output
Remote reset
+ 8~24VDC supply
- 4~20mA output
+ 4~20mA output
Flow input B
Flow input A
-0V Ground
121
-0V Ground + 8~24VDC supply
8 ~ 24 Vdc reg. suppl
y
- +
Remote reset
Note : Power supply
terminals 1 & 2 and
11 & 12 are common