Fire-Lite Alarms MS-9200 Technical Manual page 25

Figure 2.5: Style 4 Wiring: T-tapping Restrictions and Branch Resistance Figure 2.5: Style 4 Wiring: T-tapping Restrictions and Branch Resistance Figure 2.5: Style 4 Wiring: T-tapping Restrictions and Branch Resistance
Figure 2.5: Style 4 Wiring: T-tapping Restrictions and Branch Resistance Figure 2.5: Style 4 Wiring: T-tapping Restrictions and Branch Resistance
T-tapping of the SLC loop wiring is allowed for two wire (Style 4) configurations. The total resistance
of any branch cannot exceed 40 ohms. Measure the resistance as illustrated below. The total wire
length of all combined branches cannot exceed 10,000 feet.
Branch
B
Loop
Out
Figure 2.6: Style 6 Wiring Figure 2.6: Style 6 Wiring
Figure 2.6: Style 6 Wiring Figure 2.6: Style 6 Wiring Figure 2.6: Style 6 Wiring
T-tapping of the SLC loop wiring is not allowed for Style 6 configuration. The total resistance of the
complete wire run cannot exceed 40 ohms and total length cannot exceed 10,000 feet. Measure the
resistance as illustrated below.
No T-Tapping allowed No T-Tapping allowed
No T-Tapping allowed No T-Tapping allowed No T-Tapping allowed
DC Resistance of the Communications Loop DC Resistance of the Communications Loop
DC Resistance of the Communications Loop DC Resistance of the Communications Loop DC Resistance of the Communications Loop
pair cannot exceed 40 ohms. pair cannot exceed 40 ohms. pair cannot exceed 40 ohms. pair cannot exceed 40 ohms. pair cannot exceed 40 ohms.
With power removed, disconnect Loop Out and
Return at the control panel, short the two leads
of Communications Loop Return, and meter
Loop Out.
Technical Manuals Online! - http://www.tech-man.com
Branch
Branch
D
Branch
C
Branch
For each loop: For each loop: For each loop: For each loop: For each loop:
A
Add the lengths of all the branches
on one loop. This sum cannot
exceed 10,000 feet (12AWG
twisted, shielded).
(Branch A)
+ (Branch B)
+ (Branch C)
+ (Branch D)
+ (Branch E)
= 10,000 feet or less
Loop Out Return Loop
Document # 50428 Rev. B1
firealarmresources.com
E
Branch Resistance Branch Resistance Branch Resistance Branch Resistance Branch Resistance
With power removed, short the termination
point of one branch at a time and measure
DC resistance from the beginning of the
loop to the end of that particular branch.
The total DC resistance from panel to
each branch end cannot exceed 40 ohms.
Repeat this procedure for all remaining
branches.
Total length of the Communications Loop pair Total length of the Communications Loop pair Total length of the Communications Loop pair Total length of the Communications Loop pair Total length of the Communications Loop pair
cannot exceed 10,000 feet (12AWG). cannot exceed 10,000 feet (12AWG). cannot exceed 10,000 feet (12AWG). cannot exceed 10,000 feet (12AWG). cannot exceed 10,000 feet (12AWG).
B+ and B- = Output Loop
A+ and A- = Return Loop
7/28/97 P/N 50428:B1
Communications Loop Out
Branch
Loop Out Loop Out
Loop Out Loop Out Loop Out
Loop Return Loop Return Loop Return Loop Return Loop Return
25