Gill Instruments Ltd
Intrinsically Safe WindObserver Anemometer
Page 19
Issue 10
Doc. No. 1360-PS-0001
May 2015
5.2.4 Cabling
Anemometer
The Intrinsically Safe WindObserver and Power Supply Interface Box is supplied with a
3-Metre long, 3 pair, 24 AWG, screened, 8mm diameter
test cable
connected to a 20 way
Hirose connector at one end and stripped wires at the other.
A 20 way connector kit is supplied with the Anemometer to connect to customer supplied
cable.
The customer supplied cable between the Anemometer and the Power Supply Box should
be a 3 pair twisted, screened and / or armoured, and have a minimum of 0.75mm cross
sectional area and a maximum of 2.5mm cross sectional area.
The cable should meet the Cable Parameter requirements of the Sira Certificate in
Appendix 2 and IECEx Certificate in Appendix 2.
Do not attach the screen of the anemometer to earth at the junction box; it must be
attached to cable screen terminals in the PCI box via the field cable screen.
If armoured cable is used the armour must be connected to earth.
DO NOT
join the cable
armour to the screen.
Cable length
IS cable resistance must not exceed 17 ohms in each cable wire run. E.g.
If using 24 awg wire with cable resistance of 0.08 ohms per metre then maximum cable
run is 213 Metres.
If using 22 awg wire with cable resistance of 0.05 ohms per metre then maximum cable
run is 340 Metres.
It is advised that the installed cable is retained with a cable tie within 150mm of the base
of the anemometer.
If any problems of data corruption are experienced (due to, for example, a high local
electrical ‘noise’ level), then a lower baud rate should be used. Alternatively, a thicker or
higher specification cable can be tried.
Ensure that strain relief measures are employed when installing the cables. Do not allow
the whole weight of the cable to be applied to the connector.
Note: Gill Instruments do not supply Intrinsically Safe cables; it is the responsibility
of the customer to determine the type of cable that is suitable for each individual IS
installation.
Connector Assembly.
The IS WindObserver is supplied with a mating 20 way connector.
Open the pack of connector parts supplied (Gill Part 1360-PK-054).
Table of Equivalent Part Numbers
Part Name
Gill Part No.
Hirose Part No.
Connector plug, 20 way
020-02673
RM21WTP20P71
Extended backshell
1284-30-006
Not Available
Cord Clamp 8mm
020-02872
JR13WCCA-8(72)
