Electrical Power Connection and Interfacing
MAN0984_Iss 4_01/19
Touchpoint Plus
Pt. No. 3011M5001
33
Technical Handbook
5.2
Cabling and Connection Requirements
5.2.1
AC Mains Voltage Power Cables
Use a properly rated AC power cable, certified and installed in accordance with local and national regulations. The
Touchpoint Plus terminals will accept only copper wire sizes in the range 0.4 4 mm
2
(solid core), 0.4 3 mm
2
(stranded core), or 21 12 AWG (T
amb
>80 °C). The mains terminals should be torqued to 1.35 Nm (11.9 lb-in).
5.2.2
DC Power Cables
Use a properly rated DC power (mains) cable, certified and installed in accordance with local and national regulations.
The Touchpoint Plus terminals will accept only sizes 0.9 3.3 mm
2
(solid or stranded copper cores), or 18 12 AWG
(T
amb
>80 °C). The mains terminals should be torqued to 0.5 Nm (4.4 lb-in).
5.2.3
Field Device Cables
Field Device cabling (sensors, lights, solenoids, etc.) should be appropriate to the zone classification, and in
accordance with the device
recommendations. Refer to local and national regulations where
appropriate, and to the device user manual.
All sensor field cables must be screened and earthed (grounded) in order to:
•
ensure correct operation of the system
•
avoid spurious signals
•
provide lightning protection
•
Meet Standards for RFI and EMC
The I/O modules will accept copper wire sizes to a maximum of 2 mm² or 14
30 AWG, with the terminals torqued to
0.5 Nm (4.4 lb-in).
Ensure that the maximum loop resistance is not exceeded, as specified by the device manufacturer.
Ensure that the correct power level is present at the field device, as specified by the device manufacturer, and does
not exceed the TPPL supply limit of 15W per channel individually or 40 / 68 W in total. (See the notes under 5.2.5
Main Module Connections
for more details about power consumption and availability.)
E.g. if a
supply requirement is 24 VDC 0.5 A, then the power requirement is 24 V x 0.5 A (V x I) = 12 W. If you
use 240m of AWG 22 cable (R = 0.05
Ω
/m), the power line dissipation is 0.05
Ω
/m x 240m x 0.5
2
A (R x I
2
) = 3 W.
Therefore the total power requirement is 15 W (12 + 3).
You should also test the cable resistance in situ as its actual resistance is relative to T
amb
(taking into account any
added end of line resistance).
WARNINGS
All cabling shall be appropriately rated and approved in accordance with national and local regulations.
Additionally, cabling must satisfy the requirements defined in the manuals of connected field devices,
particularly if the field device is certified for use in a hazardous location.
Signal cables should be shielded to avoid spurious signals, and shall be bonded to protective earth (Ground).
Care must be taken to avoid Ground feedback loops.
All external cables should be fitted through appropriate glands to preserve the IP rating.
