Cable lengths table
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Smoke control unit - WSC 304 01
10
Ensure that the electrical cables are always routed according to the valid national and local regulations of the individual
country.
Maintaining the cable functions
The sample cable system directive (MLAR) in its current version is decisive for the type of cables and their corresponding
way of routing. In most of the German provinces, MLAR has been introduced as Technical Construction Regulation.
Various revisions of the MLAR as Technical Construction Regulation are valid in the individual provinces. Due to the fact
that the requirements with regard to the conductors for smoke control systems contained in the individual versions differ
considerably, different conductor requirements result for the individual provinces. MLAR is based on the state-of-the-art of
the year 2000 (Revision: 06/2001). In this directive, for the first time a differentiation is made between machine operated
and natural smoke ventilation systems. For natural smoke extraction systems it is sufficient to maintain the function
according to classification E30. These cables must be checked and approved in accordance with DIN 4102 Part 12. Route
the cables in conformity with the instructions of the cable manufacturers using the corresponding fastening materials.
The maintenance of the function for the smoke ventilation cables is not required if all cable paths are monitored by the
smoke detector and when the smoke and heat detection system opens as a result of the automatic detector tripping.
Concealed installation is not an approved type of installation to maintain the function in accordance with DIN 4102 Part 12.
The function is also only securely maintained by cables of class E30, or the room is monitored by smoke detectors.
The cable network for smoke ventilation systems („Cable system“) ends at the interface (junction box) for the actuator!
The flexible, heat resistant connection cable of the smoke ventilation system actuator is part of the system component
‚electric motor actuation' and does not belong to the electrical installation!
We recommend in all cases to discuss the type of cable routing with the competent fire fighting authorities.
Independent of the fact whether or not the respective MLAR is introduced in the corresponding province as
Technical Building Regulation, we recommend to point out the technical possibilities and the state-of-the-art of
MLAR 2000.
Cable length table
For determining the maximum permissible cable lengths between the smoke control unit and the actuators, taking into
account the specified cables cross sections, please refer to the following table:
Maximum motor current:
4A
(
Note:
Be aware of the overall capacity of the smoke control unit!)
Maximum cable length: (always routed from the central smoke control unit to the last junction box)
Actuating current: Sum of all motor currents per group module
Note:
Do not use the green/yellow wire!
Per motor supply line, 3 wires are required ( 2 wires current carrying /1 wire for monitoring )
Cross section
3 wire
5 wire
3 wire
5 wire
3 wire
1,5 mm²
1,5 mm²
2,5 mm²
2,5 mm²
4 mm²
Actuator current in
Amps
(2 wires in
parallel)
(2 wires in
parallel)
1
84,00 m
168,00 m
140,00 m
280,00 m
224,00 m
2
42,00 m
84,00 m
70,00 m
140,00 m
112,00 m
3
28,00 m
56,00 m
46,67 m
93,33 m
74,67 m
4
21,00 m
42,00 m
35,00 m
70,00 m
56,00 m
(The information is valid for ambient temperatures of 25°C)
Formula for the calculation of the maximum cable length
Permissible max. voltage drop in the line UL : 2 Volt
max. cable length = permissible voltage drop(
UL
) x conductivity of copper(
56
) x cable cross section(
A
)
max. actuator current total (
I
) in amps
x 2
Permissible cable length for the break glass unit supply cable when using......4x2x0.8mm:
up to 200m
The motor connection cable length to the junction box (or control module) must not exceed
10 m
.
