Four-Wire Smoke Detectors - Fire-Lite Sensiscan 200 Installation, Operation, And Programming Manual

Four-Wire Smoke Detectors

Initiating devices requiring 24 VDC operating power can be wired as illustrated in Figures 6-4 and 6-5.
IZ-4AF
or IZ-8F with IZE-AF
Initiating Device Circuit
24VDC Power Supply
Power-limited, UL listed for Fire
Protective Signaling
MPS-24BPCC
TB2 Term. 1 (+) & 2 (-)
IZ-4F or IZ-8F
Initiating Device Circuit
24VDC Power Supply
Power-limited, UL listed for Fire
Protective Signaling
MPS-24BPCC
TB2 Term. 1 (+) & 2 (-)
Notes on Style B and Style D field wiring:
1) The Power Supervision Relay coil leads must be connected to the last detector base 24V screw terminal.
2) Calculation of the maximum allowable resistance in the 24VDC detector power wiring:
R = (20.6 - V
MAX
(N)(I ) + (NA)(I
S
R — is the maximum total resistance of the 24-volt power circuits.
MAX
V — is the minimum operating voltage of the detector or end of line relay, whichever is greater, in volts.
OM
N — is the total number of detectors on the 24V supply loop.
I — is the detector current in standby.
S
NA — is the number of detectors on the 24V power loop which must function at the same time in alarm.
I — is the detector current in alarm.
A
I — is the end-of-line relay current.
R
40
-
+
+
-
Four-Wire Smoke Detectors
+
-
Employing Four-Wire Smoke Detectors (Style D)
+
-
+
-
Employing Four-Wire Smoke Detectors (Style B)
)
OM
where:
) + (I )
A R
Sensiscan 200 15032 Rev C1 11/1/96 P/N 15032:C1
IDC(+)
IDC(-)
24 VDC (+)
Common (-)
UL-listed 24 VDC
Figure 6-4:
All connections are supervised and power limited
IDC(+)
IDC(-)
24 VDC (+)
Common (-)
UL-listed 24 VDC
Four-Wire Smoke Detectors
Figure 6-5:
All connections are supervised and power limited
NC
C
+24 VDC
-0 VDC
UL Listed Power
Supervision
Relay
4.7K
NC
ELR
C
+24 VDC
-0 VDC
UL Listed Power
Supervision
Relay