Technical Bulletin
Document No. 125-3596
January 8, 2013
Wiring Guidelines for Gamma Lighting Control Circuits
This wiring guideline applies to KNX TP1 Bus, Analog (1-10V) Dimming Control, and
Digital Addressable Lighting Interface (DALI) Control used with Gamma lighting
controls sold in North America.
KNX-certified TP1 cable, Analog Dimming cable and DALI cable, which are
manufactured by most global wiring suppliers, are not currently listed for use on 277V
lighting circuits or available in North America. This guideline specifies alternative 300V
cables that are available for lighting voltages up to 277V. For 347V lighting circuits
600V power limited tray cable should be used.
Cable is consolidated into two types:

Shielded pair 18 AWG solid 300V plenum for KNX TP1 Bus

Unshielded pair 18 AWG stranded 300V plenum for both Analog (1 – 10V) and
DALI dimming control.
Only 300V plenum rated cable is sourced as most lighting control enters a plenum
space at some point. Suppliers also have non-plenum 600V versions, but pricing is
typically based on volume so non-plenum and 600V versions are not sourced. For
more information, see the Cable Specifications and Sourcing [➙ 5] section.
CAUTION
All Gamma power wiring changes must be done by an electrician.
Lighting control cable wiring may be done by authorized personal except were codes
require work to be performed by an electrician.
There is no protection of the Lighting Control Bus or Dimming circuits against
destruction by accidental connection to AC line voltage! Ensure electrical separation
of lighting control conductors from lighting power conductors.
KNX TP1 Bus Cable
KNX is an International Standard used as the protocol for Gamma lighting control
devices. Twisted Pair 1 (TP1) is the communication specification including signal,
power and cable type connecting up to 64 devices, such as switches, sensors, relays
and interfaces. The connection is electrically referred to as the bus and logically
referred to as a line. A lighting control system may have many lines. All lengths in this
guideline refer to a single bus or line.

The recommended bus cable is 18 AWG solid copper shielded twisted pair that is
rated 300V plenum.
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Siemens Industry, Inc.
Gamma Lighting Control Wiring Guidelines
125-3596
2013-01-08
Wiring Guidelines for Gamma Lighting Control Circuits

Cable installation can reach its maximum length with three 1000 ft branches from
the power supply. Other topologies are allowed as long as they do not exceed the
maximum length.

Alternative cable segment length is based on comparison of DC resistance and
conductor capacitance with KNX-certified 0.8 mm2 (20 AWG) cable. Lengths
shown in the following Table meet the KNX time delay specifications.
Table 1:
Maximum Length of a TP1 Bus using Alternative Cable.
Description of Cable Segment
6320FE 8771000
Power Supply to End-of-Line Device
1000 ft
End of Line Device to End-of-Line Device
2000 ft
Total Cable Length (due to impedance)
3000 ft
Maximum Parallel Run with Lighting Power
150 ft
Bus voltage is 29 Vdc maximum at the power supply and decreases across the cable
as current is drawn from all devices. Since 18 AWG wire gauge is used, there will be
no loop resistance issues maintaining a minimum of 22 Vdc between the red (+)
terminal and black (–) terminal for the lengths shown in the Table.

Devices communicate at 9600 bps data rate with passive high and active low
signals using the same conductors as the bus power.

End-of-line terminators are not required.

The maximum lengths stated in the Table for the recommended cable ensure total
capacitance for proper communication.

Bus cable 300V insulation allows use with up to 277 Vac lighting circuits.

Bus conductors must be terminated separate from line voltage and must not be in
parallel to the line voltage for runs longer than those shown in the Table.

Both bus conductors must be isolated from ground. This is referred to as separated
extra-low voltage (SELV).
–
Only the power supply PE terminal is connected to protective earth ground to
prevent static charge build up on the bus.
–
Power supply output between the red (+) terminal and black (–) terminal is held
to a maximum of 14 Vdc at the red (+) terminal with respect to the PE terminal.
–
The shield is used as a magnetic barrier that is left floating. During installation,
tie back the shields at both ends. If needed later, connect one end of the shield
to the same protective earth ground as the PE terminal on the power supply
and wire nut remaining shields at each TP1 bus terminator.
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Siemens Industry, Inc.
Gamma Lighting Control Wiring Guidelines
125-3596
2013-01-08
Cable Specifications and Sourcing
Analog (1 to 10V) Dimming Control Cable
CAUTION
The electrician must ensure that, when looping lighting power through the dimming
actuator switching relay L-conductors, the maximum connection current of 20A is not
exceeded and that the cable and product are protected by the appropriate lighting
power circuit breaker.
Each analog dimming control channel will sink 1 to 10 Vdc from up to 60 sourcing-type
dimming ballasts. Each dimming channel may be logically grouped with an ON/OFF
dry contact relay for the lighting power.

The recommended dimming control cable is 18 AWG stranded unshielded twisted
pair that is rated 300V plenum. HVAC signal cable is used for this application.

Nominal voltage must not exceed 277V for any cable run in the same conduit or
tray with dimming control cable.

New installations of lighting panels must run both the dimming control cable and
the lighting power cable from the actuator in the lighting panel to the ballast. The
electrician will determine the lighting power cable length, gauge, current-limiting
and separation.

Retrofits to lighting panels only require that new dimming control cable be run and
that an electrician change out the lighting power connections and dimming control
cable connections at the lighting panel and new dimming ballast. Also run KNX bus
wire to each actuator in the lighting panel.

Retrofits without lighting panels may also be done by installing the analog dimming
actuator locally in a utility enclosure at the wire split-off for each circuit to minimize
rewiring the lighting power. KNX bus cable must also be run to each local dimming
actuator.

The ballast manufacturer specifies the required compliance voltage and operating
current. Typical dimming ballasts require a 2 Vdc minimum compliance at 10 Vdc
maximum signal and 2 mA maximum sinking capability. Including overhead and
equipment variance, each dimming channel should be planned to sink 250 mA for
control of up to 60 standard ballasts. Calculate the distance using 4 mA per ballast.

Dimming ballast control requires polarized twisted pair cable, but does not require
shielding.
The following Table shows the maximum cable length from each dimming control
channel to the furthest dimming ballast in the group.
Table 2:
Maximum Length of a Single Dimming 1 to 10V Control Cable
Description of Cable Segment
H-TP18-CMP
Cable length to furthest ballast in maximum group of 60 ballasts
640 ft
Cable length to furthest ballast in maximum group of 10 ballasts 1
6,400 ft
Cable length to a single ballast only1
38,400 ft
1)
Using extended lengths and reduced number of ballasts on a circuit is not reversible without rewiring.
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Siemens Industry, Inc.
Gamma Lighting Control Wiring Guidelines
125-3596
2013-01-08
Wiring Guidelines for Gamma Lighting Control Circuits
DALI Control Cable
DALI Control Cable
Each KNX/DALI Gateway N 141/02 controls a single channel of up to 64 DALI ballasts.

The recommended dimming control cable is 18 AWG stranded unshielded twisted
pair that is rated 300V plenum. HVAC signal cable is used for this application.

Nominal voltage must not exceed 277V for any cable run in the same conduit or
tray with dimming control cable.

Since DALI serves the same purpose as Analog Dimming, the same 18 AWG
stranded unshielded twisted pair is also recommended to reduce lighting control
cable types.

Both new and retrofit installations may run the lighting power independent of the
DALI control cable and take advantage of separating lighting power planning from
control planning.

DALI control cable does not require twists, polarity or shielding, but most DALI
controls and ballasts have + and – terminals or other consistent marking, which
does not conflict with recommended cable black and white conductor insulation.

Where multiple phases of line power are used for ballasts in the same DALI group,
local codes may require control cable polarization.

KNX bus cable must also be run to each DALI Gateway N 141/02.

DALI bus voltage is ~ 16V floating ranging from 22.4V to 9.5V. DALI control signal
operates at 1200 bps data rate.
The following Table shows the cable type and maximum length from the DALI control
channel to the furthest DALI ballast-based 250 mA maximum total load and 2V
compliance. Typically, this length will not be increased by limiting the maximum
number of ballasts on the DALI control circuit. Instead, install the DALI Gateway N
141/02 within the maximum distance from the furthest ballast and run KNX bus to the
gateway.
Table 3:
Maximum Length of a single DALI Control Cable
Description of Cable Segment
DALI control channel cable length to the furthest of 64 DALI
dimming ballasts
H-TP18-CMP
640 ft
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Gamma Lighting Control Wiring Guidelines
125-3596
2013-01-08
Cable Specifications and Sourcing
Cable Specifications and Sourcing
Table 4:
6320FE 8771000 Communications Cable
Wire and Cable Specification - Required Information.
Description
COMMUNICATION CBL 18AWG,SOL,2CS,CMP, WHITE
JACKET
Specifications
Number of pairs
1
Resistance DCR: 6.385 Ω/1000 ft nominal
Gauge and stranding
18 AWG (1-BC)
Capacitance C-C: 70 pF/ft nominal
Primary insulation type
LSPVC
Twists per foot: 4 nominal
Nominal Insulation thickness
0.009”
Jacket Material: LSPVC
Color code
RED/BLK
Nominal Jacket thickness: 0.015”
Shield type(Tape, Braid)
TAPE
Jacket color: White
Shield coverage
100%
Nominal O.D.: 0.150”
Tape
Shorting Fold
Packaging: 1000 ft
Drain wire
20 AWG 7 × 28
NEC/UL/CEC/CUL: CMP
Braid construction
N/A
Voltage rating: 300V
Impedance(1, 10, 100 Mhz)
N/A
UL Temp rating: 75°C minimum
Print Legend: NEW GENERATION® BY BELDEN 6320FE CMP 75C 2C18 SHIELDED (UL)
C(UL) ROHS (Plus Mfg E#)
NOTE: Sequential footage markers required.
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Siemens Industry, Inc.
Gamma Lighting Control Wiring Guidelines
125-3596
2013-01-08
Cable Specifications and Sourcing
Table 5:
H-TP18-CMP and H-TP18-CMP-Box
Wire and Cable Specification - Required Information.
Description
HVAC CBL 18AWG,STR,1TP,CMP, BLUE JACKET
Specifications
Number of pairs
1
Resistance DCR: 6.92 Ω/1000 ft nominal
Gauge and stranding
18 AWG (7 × 26)
Capacitance: N/A
Primary insulation type
PRPVC
Twists per foot: 4 nominal
Nominal Insulation thickness
0.009”
Jacket Material: PRPVC
Color code
BLK/WHT
Nominal Jacket thickness: 0.015”
Shield type(Tape, Braid)
N/A
Jacket color: Blue
Shield coverage
N/A
Nominal O.D.: 0.155”
Tape
N/A
Packaging: 1000 ft
Drain wire
N/A
UL type: CMP
Braid construction
N/A
Voltage rating: 300V
Impedance(1, 10, 100 Mhz)
NA
Temp rating: 75°C minimum
Print Legend: NORTHFLEX® H-TP18-CMP “DI, DO, AI, AO” 18 AWG 2C 75°C CMP (UL)
C(UL) (Plus Mfg E#)
NOTE: Sequential footage markers (1000 descending to 0) required.
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Gamma Lighting Control Wiring Guidelines
125-3596
2013-01-08
Table 6:
Lighting Control Cable Sourced through Anixter.
Siemens Part
Number
Supplier Part Number
Description
Plenum
Applications
Price per
1000 ft 1)
H-TP18-CMP
H-TP18-CMP 2)
HVAC cable, 18 AWG, STR,
1 TP, CMP, blue jacket
Yes
DI, DO, AI, AO;
Analog (1-10V)
Dimming;
DALI Control Bus
$88
H-TP18-CMP-BOX
H-TP18-CMP-BOX 2)
HVAC cable, 18 AWG, STR,
1 TP, CMP, blue jacket – box
Yes
DI,DO,AI,AO;
Analog (1-10V)
Dimming;
DALI Control Bus
$88
N/A
6320FE 8771000 2) 3)
Communication cable,
18 AWG, SOL, 2 CS, CMP,
white jacket
Yes
KNX TP1 Bus – Only!
$140
1)
Pricing for Siemens Industry based on 1000 ft reel or box, 50 units per year, and typical 3-week lead-time. Other business unit pricing
may vary.
2)
Non-plenum numbers are H-TP18-CMR(-BOX) and 5320FE 88771000, respectively.
3)
The New Generation® by Belden description still contains “2C” for “2 conductor”, but it is actually now twisted pair.
Information in this document is based on specifications believed correct at the time of publication. The right is reserved to make changes as
design improvements are introduced. Product or company names mentioned herein may be the trademarks of their respective owners. ©
2013 Siemens Industry, Inc.
Siemens Industry, Inc.
Building Technologies Division
1000 Deerfield Parkway
Buffalo Grove, IL 60089-4513
USA
Tel. 1 + 847-215-1000
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Document No. 125-3596
Printed in the USA
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