5.4.1
Connection of frequency converter/MPR-relay
This example shows which inputs/outputs on the EBC24 need to be connected to the frequency converter/MPR-relay.
• Connect the supply to terminals 1-3.
• Loop terminals 13 & 28.
• Connecting the boiler:
• Connect the burner start signal to terminals 14 & 15.
• Connect the potential free contact to terminals 12 & 29.
• Frequency converter
• Connect terminals 7 & 8 to the start/stop input on the frequency converter.
• Connect terminals 20 & 21 input for external speed regulation.
• If needed, connect terminals 30 and 32 to the alarm output of the frequency converter.
• Connect the pressure transducer (XTP) to terminals 22-24 with a shielded cable, and connect the dis-
play to terminal 6
1
2
3
4
5
6
7
8
SUPPLY IN
VFD Out
L1
N
N
FAN MOTOR
OUT
REG
NO
C
NC
NO
C
+/
~
-/~
+/
~
-/~
NO
C
ALARM OUT
BOILER
1 - IN
BURNER
1 - OUT
BOILER
2 - IN
BURNER
2 - OUT
C
NO
24 VDC
0V
24V
NC
NO
C
24V
NO
PDS
BUZZER
VFD
0V
0-
10V
0V
24V
0-
10V
0V
A
B
XTP
RS485
3120073-UK EBC24
26
• Pressure-controlled regulation
