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INM 725B Rev 21
3
LOGIC SUPPLY & FUSING
All RTK 725B Alarm Annunciators operate from a 24VDC logic supply.
Any external power supply connected to the annunciator must be compliant to UL60950 or
EN60950 or suitable equivalent standards.
3 .1 Externally Powered Systems
When external power supplies are used 24VDC must be connected to terminals OV and +V as
shown below.
Fuse F1, (5 x 20mm 5A), is provided on the underside of the power input card to protect the
alarm logic and +24VDC is internally linked to all of the associated cards within the system.
Red LED
F1
is used to indicate that the +V fuse has blown.
Fuses
FU-1A-002 - 5 x 20mm 1A signal supply fuse
FU-5A-003 - 5 x 20mm 5A logic supply fuse
3 .2 SI/O Card Versions
Part No
Description
CB6648POP1
Used on standard versions with remote power supplies
CB6648POP3
Used on versions with RS485 communications & remote power supplies
REAR VIEW
OV OV
+V
+V
0VC +VC
Rx
F1
F2
Tx
FROM EXTERNAL
24VDC SUPPLY
(+)
(OV)
F1
UNDERSIDE VIEW OF
POWER INPUT CARD
F2
5A / T
1A / F
1A / F
LOGIC
SUPPLY
FUSE
SIGNAL
SUPPLY
FUSE