Four-Wire Smoke Detectors - Fire-Lite The 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 6-5 and 6-6.
IZ-4AF
or IZ-8F with IZE-AF
Initiating Device Circuit
24 VDC Power Supply
Power-limited, UL listed for Fire
Protective Signaling
MPS-24BPCA
TB2 Term. 1 (+) & 2 (-)
IZ-4F or IZ-8F
Initiating Device Circuit
24 VDC Power Supply
Power-limited, UL listed for Fire
Protective Signaling
MPS-24BPCA
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 24 VDC screw terminal.
2) Calculation of the maximum allowable resistance in the 24 VDC detector power wiring:
R = (20.6 - V
MAX
(N)(I ) + (NA)(I
S
R – is the maximum total resistance of the 24 VDC power circuits.
MAX
V – is the minimum operating voltage of the detector or end of line relay, whichever is greater.
OM
N – is the total number of detectors on the 24 VDC supply loop.
I – is the detector current in standby.
S
NA – is the number of detectors on the 24 VDC 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
-
+
+
-
Four-Wire Smoke Detectors
+
-
Employing Four-Wire Smoke Detectors (Style D)
+
-
+
-
Employing Four-Wire Smoke Detectors (Style B)
)
OM
where:
) + (I )
A R
S200 15032 Rev C 02/22/96 P/N 15032:C
IDC(+)
IDC(-)
24 VDC (+)
Common (-)
UL-listed 24 VDC
Figure 6-5:
All connections are supervised and power limited
IDC(+)
IDC(-)
24 VDC (+)
Common (-)
UL-listed 24 VDC
Four-Wire Smoke Detectors
Figure 6-6:
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
41