4
ELECTRICAL CONNECTIONS
16
TT 51 SERIES
www.krohne.com
08/2015 - 4000754203 - MA TT 51 R03 en
Electrical connections
4.1 Safety instructions
4.2 Electrical connections of in-head transmitter
The input and output signals and the power supply must be connected in accordance with the
following illustrations. The transmitter is easy to install with the connection head installation kit.
To avoid measuring errors, all cables must be connected properly and the screws tightened
correctly.
DANGER!
All work on the electrical connections may only be carried out with the power disconnected. Take
note of the voltage data on the nameplate!
DANGER!
Observe the national regulations for electrical installations!
DANGER!
The transmitter is protected against polarity reversal. No damage will occur to the device if the
polarity of the supply voltage is switched. The output will then indicate 0 mA.
DANGER!
In potentially explosive areas, the intrinsically safe versions must be used.
The TT 51 C (intrinsically safe) can be installed in potentially hazardous area zone 0, 1 and 2.
The TT 51 R (intrinsically safe) can be installed in potentially hazardous area zone 1 and 2 and the
input may be connected to temperature sensors installed in zone 0.
The intrinsically safe versions must be supplied by an intrinsically safe power supply unit or
Zener barrier placed outside of the potentially explosive zone.
WARNING!
Observe without fail the local occupational health and safety regulations. Any work done on the
electrical components of the measuring device may only be carried out by properly trained
specialists.
INFORMATION!
Look at the device nameplate to ensure that the device is delivered according to your order.
Check for the correct supply voltage printed on the nameplate.
DANGER!
For the transmitters used in hazardous areas following special conditions have to be considered:
The communication port (USB connection) may only be connected to the associated ICON
interface if the temperature transmitter is outside the hazardous area and with no sensor
connected to it that is in the hazardous area.
For the permitted ambient temperature range, refer to Temperature data for areas with
potentially explosive atmospheres on page 48
.
The transmitter shall be mounted into a suitable enclosure that provides a degree of protection
of at least IP20.
MA_OPTITEMP_TT_51_en_150828_4000754203_R03.book Page 16 Friday, August 28, 2015 10:54 AM
