INM 5500 Rev 11
74
10 .4 MTL5314 trip amplifier for 2– or 3– wire transmitters
The MTL5314 connects to a 2– or 3– wire 4 to 2mA transmitter or current source located
in the hazardous area. It supplies one or two configurable alarm signals to the safe area via
changeover relays. Each relay may be configured individually to signal an alarm condition when
the input signal is greater than or less than a pre-set value.
In addition, the MTL5314 can be connected in to the hazardous area side of an MTL5042 4 to
20mA repeater power supply (or equivalent device) to provide two trip alarm outputs direct from
the transmitter signal (see schematic diagram). Looping the transmitter signal through the MTL
5314 (via terminals 1 and 3) does not affect HART® communications.
Terminals 1 and 3 meet clause 5.4 of EN50020: 1994 and have the following parameters:
U ≤ 1.5V, I ≤ 0.1A, P ≤ 25mW. They can be connected without further certification into an IS
loop with open circuit voltage of not more than 28V. See certificate for further details.
10 .4 .1 Wiring connections
If terminals 1 and 3 provide a 4 to 20mA loop to a HART transmitter, HART communication can
be superimposed on the 4 to 20mA signal.
Note:
Reactive loads must be adequately suppressed.
Figure 10.6: MTL5314 wiring diagram and connections
Hazardous area
Safe area
