ELIS PLZEŇ a. s.
Project design, installation and service manual
Page 26 of 72
Electromagnetic flowmeter FLONET FH30xx
ELIS PLZE
Ň a. s., Luční 425/15, 301 00 Plzeň, Czech Republic, phone.: +420 377 517 711, fax: +420 377 517 722
Es 90678K
4.6 Thermal insulation
When installed in thermally insulated piping, to prevent unnecessary heat loss, the meter sensor is
usually provided with thermal insulation too.
In such cases, the following rules need be observed:
•
Insulation shall be applied onto the meter sensor only;
•
Maximum surface temperature of the sensor, whether thermally insulated or not, shall not exceed
the values given in Section 3.4;
•
The maximum insulation thickness shall not exceed 40mm (the thermal conductivity coefficient
λ
D
≤
0.045 (Wm
-1
K
-1
) at 50
C; see standard EN 13787);
•
In the cases of compact meter version, the part connecting the meter sensor and transmitter shall
always remain bare;
•
The transmitter shall be protected from additional heating (by direct sunshine or heat emanating from
nearby equipment).
4.7
Flowmeter heating
In measuring fluids with sub-zero operational temperatures, or at ambient temperatures close to the
specified minimum fluid temperatures, it is permitted to provide the meter sensor with thermal insulation
and auxiliary heating system.
•
The sensor heating can be facilitated by electricity or a suitable heat-carrying medium supplied
through a special piping system;
•
In cases of electric heating, it is recommended to use a regulated AC power source with current
switching at zero.
5 ELECTRICAL CONNECTIONS
5.1 Transmitter
5.1.1 Terminal box
Terminals
AC power source
L
95 to 250VAC, 45 to 65Hz
N
PE
