Dwyer MTL5045 User Manual
Page 34
30
INM5000-6 Jul 2010
6.32.2
Trip calibration
Switches and multiturn potentiometers for setting the trip points are
located on top of the unit (see figure 6.74). For each of channels A and
B:
i
Set trip switch to H (high) or L (low) as required (see table 6.15
for relay operation).
ii Set input current to the required value for trip-point.
iii Adjust SET A/SET B until LED A/B is on: then slowly adjust until
LED goes out.
iv Relays are energised in normal operation and de-energised when
tripped. A lit LED shows the safe condition (not tripped).
Table 6.15
– = Either option
✫ = LED On • = LED Off
6.32.3
Testing
Make the safe- and hazardous-area connections shown in figure 6.75
and carry out the following procedure:
a
Set the current source or sink to 12mA
b
Adjust each trip potentiometer until the associated LED just
extinguishes.
c
With sources of 11.5mA and 12.5mA carry out the following
checks:
6
5
4
3
2
1
7
8
9
10
11
12
13
14
6
5
4
3
2
1
7
8
9
10
11
12
13
14
Vs
Vs+
20 to 35V dc
Trip B
Trip A
Vs
Vs+
20 to 35V dc
+
4/20mA
Load
+
4/20mA
* Hand-held communicator
6
5
4
3
2
1
7
8
9
10
11
12
13
14
I
I
Vs
Vs+
20 to 35V dc
Trip B
Trip A
+
HHC*
HHC*
+
4/20mA
4/20mA
+
+
MTL5314
MTL5042
MTL5314
Figure 6.73: MTL5314 wiring diagram and connections
Terminal
Function
1
Current input
2
Transmitter supply +ve
3
Common
7
Trip B (NC)
8
Trip B (COM)
9
Trip B (NO)
10
Trip A (NC)
11
Trip A (COM)
12
Trip A (NO)
13
Supply –ve
14
Supply +ve
Hazardous area
Safe area
H
H
SET
A
MTL5314
PWR
LF
PR
CH1
ON
L
L
SET
B
A B
Figure 6.74: Top label, MTL5314, showing positions of trip
switches and multiturn potentiometers
Trip
Operation
PWR A or B
Relay contacts
switch
LED
LED
11-12
10-11
A or B
8-9
7-8
H (high)
Input >Trip setting
✫
•
open
closed
H (high)
Input ✫ ✫ closed open L (low) Input >Trip setting ✫ ✫ closed open L (low) Input ✫ • open closed – – • • open closed 6 5 4 2 1 7 8 9 10 11 12 13 14 Vs Vs+ 20 to 35V dc Trip B Trip A Source or sink I I + High alarm Low alarm Relay Relay LED 11-12 10-11 LED 11-12 10 -11 Current 8 - 9 7 - 8 8 - 9 7 - 8 11.5mA On Closed Open Off Open Closed 12.5mA Off Open Closed On Closed Open Figure 6.75: Test circuit for MTL5314
3