iSMA-B-FCU Hardware User Manual
www.ismacontrolli.com
DMP242en | 1st Issue rev. 3 | 02/2022
page 9 of 53
Figure 2. 230 V AC power supply
The iSMA-B-FCU-LL version is designed to work with the 24 V AC power supply. The
device is equipped with a built-in
6 A
fuse protecting the controller and the connected 24
V AC equipment.
Figure 3. 24 V AC power supply
Note:
Total current for digital relay outputs O1-O4 cannot exceed 6A.
4.2.1 24 V AC Power Supply for External Equipment
The iSMA-B-FCU-HH is equipped with a 24 V AC, 7 VA power supply output to supply an
external equipment like sensors and actuators. This power supply uses a separate coil in
the transformer. The 24 V AC power supply terminal connection is labeled L2, N2.
The iSMA-B-FCU-HL is equipped with a 24 V AC power supply output for thermal valves
controlled by triac outputs and external devices like sensors and actuators. This power
supply uses a separate coil in the transformer. The 24 V AC power supply terminal
connection is labeled L2, N2. The total power consumption with thermal valves and
external devices cannot exceed 7 VA
(~0.3 A).
The iSMA-B-FCU-LL is equipped with a 24 V AC, 7 VA power supply output to supply the
external equipment like sensors and actuators. This power supply uses a separate 24 V
AC transformer. The external separate power supply terminal connection is labeled L2,
N2.
4.3 Terminals and Internal Connections
There are 3 types of hardware available:
WARNING!
It is forbidden to use a fuse with current exceeding 6 A! Higher current
may permanently damage the device and cause danger to the user and to the
equipment!
