Environment
To achieve the best possible lifetime out of your EXCOUNT-II trans- ceiver, avoid exposure to strong sunlight for extended periods, hot temperatures (over +50 º C), cold temperatures (under -10 º C ) and water (the design is showerproof but not watertight).
Cleaning
To clean the transceiver use only a damp soft cloth with a mild detergent.
Changing the battery
The transceiver is powered by a 9 volt battery. Always check the bat- tery status before going to site to take measurements. Replace it when necessary with type 6LR61/PP3.
NOTE! Used batteries should NOT simply be thrown away. Return the battery to a recovery station or leave it with your local ABB representative for environmentally friendly disposal.
4. Using the transceiver
4.1 Transceiver functions
Figure 4.1.1
Switch the transceiver on/off To turn on the transceiver press To turn off the transceiver press
The transceiver turns itself off automatically after 5 minutes.
External antenna connection
Battery cover Protective cover
EXCOUNT-II
Data cable connection Enter
Increase value Display screen
Decrease value
Move down Move up Go back
4. Using the transceiver
4.1.1 Use of external hand-held antenna
A separate hand-held external antenna is available as an option for use in special applications which require greater signal strength than is possible to achieve with the transceiver’s internal antenna.
When the external antenna is to be used, the following steps should be followed:
a) Remove the protective cover from the external antenna connection on the underside of the transceiver.
b) Fit and hand-tighten the external antenna to the connection point.
c) Turn on the transceiver and enable the external antenna from the settings menu as described in section 5.4.2.
d) Make measurements, following the guidelines given in Section 4 of this User’s Manual. Note that the external antenna must be pointed directly at the sensor´s in-built antenna in order to obtain the optimum signal strength.
e) After completing the measurements, carefully unscrew the external antenna and replace the protective cover on the transceiver.
f) In case the next measurements are to be made without the external antenna, re-enable the internal antenna from the settings menu as described in section 5.4.2.
Note! Difficulties in communication can occur if attempting to make measurements with the external antenna enabled but not connected.
4. Using the transceiver
4.2 Transceiver symbols
Stand by Operation performed
successfully
Establishing contact Operation performed
un-successfully
Active field xxx-yyyy-zzz Sensor ID
Transfer data Data transfer from PC
to transceiver
Read data Data transfer from
transceiver to PC
Battery check Battery condition
Leakage current
measurement Settings
Resistive leakage
current measurement * Date & clock Read surge counter
data Antenna
Total reading * Backlight
Operating voltage * Contrast
* Not avaiable in all versions
A B B
> > > > > > >
4. Using the transceiver
4.3 Flowchart, making measurements
The main menu is accessed by pressing
enter Press to turn on the transceiver
1. Prepare the transceiver for measurements
See 5.1.1
Set the transceiver to
"Prepare the transceiver for measurements" mode.
Connect the transceiver to the PC
via the data cable.
Select which Sensors are to be read by station, position
and phase.
Select Sensor ID from the menu in the transceiver
and press enter.
Different types of measurements can be performed by following the instructions in 5.3.
Click "Send list to transceiver" when ready.
This erases all stored data in the transceiver.
2. Make measurements
See 5.3 3. Transmit data to the EXCOUNT-II software
See 5.1.2
Set the transceiver to
"Data transfer from Transceiver to PC" mode.
Connect the transceiver to the PC via the data cable
Open the EXCOUNT-II PC software and select "Transfer
data" followed by
"Receive measured data from transceiver".
Click "Request data"
when ready.
Click "save" to store the details in the database.
Before going to the site check the battery status.
See 5.2.
Then turn off the transceiver to conserve the battery.
Ensure the sensor to be read is within range and orientation for
transmission, see section 4.5 to 4.10
Set the transceiver to "Make measurements" mode.
Open the EXCOUNT-II PC- software and select "Transfer
data" followed by "Prepare transceiver for measurement".
Check that the date and time on the transceiver are synchronized with the settings
on the PC. See 4.4
Check that the date and time on the transceiver are synchronized with the settings
on the PC. See 4.4
4. Using the transceiver
4.4 Sychronization of the clocks
Prior to transfering data between the PC and the transceiver, it is important to check that the date and time are sychronized between both of them. See figure 4.1.1 and 4.1.2. If not, set them as described in section 5.4. If this is not done, the date stamp from the sensor will be incorrect, which can lead to difficulties in recording measurements.
Figure 4.1.1 Windows date/time
properties menu
Figure 4.1.2 Transceiver date/time
properties menu
4. Using the transceiver
4.5 Range of the communication
Direct and completely unobstructed line-of-sight is preferable between the transceiver and the sensor during communication.
The transceiver can communicate with the sensor within a range of up to 60 meters. However this may differ depending on external factors, including the physical and geographical layout at the site or the presence of radio disturbances in the vicinity. A separate (optional) external hand-held antenna is available to boost the effective signal strength and increase the communication distance in special confi- gurations which require it. However to obtain the best possible signal strength, see section 4.6 to 4.9 below.
4.6 Your body affects the signal strength
Keep the transceiver as far away as possible from your body (arm- length), since your body acts to diminish the energy from the trans- mitter. The antenna is located in the top of the transceiver, so do not place your hands or other obstructions over this area.
4.7 Optimal direction of the internal transceiver antenna
The signal strength between the antennas in the transceiver and sensor are influenced by their orientation to each other. See figure 4.7.1 for the best performance from the transceiver when used alone.
Note that the best reception and maximum range is obtained by poin- ting the transceiver at approximately right angles to the sensor instead
of directly at it. 0°
180°
90°
270°
Strength
Optim al dir
ection Optimal direction
4. Using the transceiver
4.8 Direction of the sensor antenna
It may seem logical to be as close as possible to the sensor to obtain the highest signal strength. However, this is not the case since the sensor antenna has a signal direction which is nearly horizontal, see figure 4.8.1 depicting the contact zone.
To achieve the highest signal strength, you should stand a distance away which is equivalent to twice the height of the sensor above the ground plane. As noted in section 4.7, facing almost 90° degrees to the sensor will also assist in optimizing the signal strength.
Figure 4.8.1
Optimal direction of the sensor antenna
Since EXCOUNT-II relies on radio communication to make contact between the transceiver and sensor, so called ”dead zones” can exist, whereby the location you are standing at does not permit adequate signal strength. If a measurement is attempted in one of these zones, an Error code 80 or 82 may appear on the transceiver. Taking a few paces to move out of the ”dead zone” before retransmitting again is often all that is needed to permit contact to be established between the transceiver and sensor.
Optimal direction
Sensor
Height
2 x Height
4. Using the transceiver
4.9 Special configurations
If the sensor is located a significant height above the ground, it may be dif- ficult to make contact since it is not practical to be within the contact zone as described in section 4.8. Examples are tall transmission line towers and gantries. The taller the structure, the smaller the contact zone at ground level.
For these special configurations, a separate hand-held external antenna is available as an option. This is a directed antenna which focuses the signal in order to boost the effective strength and thereby increase the communication distance. Since the signal is directed, the external antenna must be pointed directly at the sensor’s in-built antenna in order to obtain the optimum signal strength.
Direct and completely unobstructed line-of-sight is preferable between the transceiver antenna and the sensor during communication. The first attempt for communication should always follow the guidelines given in section 4.8, but with the external antenna pointed directly at the sensor. If difficulties are experienced, trial different locations around the sensor. Note that different contact zones may apply for each phase or individual readings (see section 4.10). If necessary, and is possible to do safely, it is recommended to finally stand directly under the sensor while making measurements using the exter- nal antenna in such special configurations. See figure 4.9.1.
Figure 4.9.1
Use of hand-held external antenna in special configurations Use of the external antenna may even assist communication in standard configurations which otherwise have difficulty making contact because of
Optimal direction Transceiver
antenna 90o
4. Using the transceiver
4.9.1 Tower and Gantry layout
Experience has shown that specific special configurations, arrangements, locations, geography etc can affect the robustness of the performance of EXCOUNT-II. For this reason, it is strongly recommend undertaking a field trial prior to full-scale installation. Since many factors are inter-related, a simple trial made at the base of the transmission tower or gantry may not be adequate to guarantee performance when mounted in service.
Instead, what is preferred is a trial with sensors fitted on a 3-phase set of arresters mounted on each different tower/gantry configuration under consideration. Communication should be checked both with the line de- energized and energized. The final functionality at a given location with a specific special configuration can then be determined.
As a further consideration, whilst the use of the external antenna may assist in achieving effective communication, the tower/gantry layout and configuration can affect the ultimate accuracy of the resistive leakage current measurements (if available), since the positioning of the surge arresters in relation to each other may alter the field-strength factor based in the measuring principle (refer section 6). See figure 4.9.2 for example.
In such cases, the measured values must be treated subjectively. Nevert- heless, absolute values are of lesser interest, since a rising trend gives a better indication of potential arrester deterioration over time.
Figure 4.9.2
4. Using the transceiver
4.10 Total versus Individual readings
Attempts to make a total reading (available in extended version only) – i.e. consecutively leakage current, surge count, resistive current – may be inappropriate with certain configurations and generate errors, since the information is “in the air” too long. Should this occur, individual readings of the separate measurements need to be made instead. See section 5.3. Note that different contact zones may apply for each indivi- dual reading.
4.11 Measurement strategy
To avoid unnecessary outages plus the high cost of unwarranted testing of arresters, a decision should be made on a suitable time interval for regular reading of the EXCOUNT-II data. This interval depends on a number of factors including network arrangement, lightning flash density, system redundancy, resources, desired accuracy in time-stamp, etc.
As a guide, the following strategy for a schedule of taking measurements is proposed to begin with:
• Always a short time directly after energization to obtain a reference value.
• At regular time intervals, determined by site availability and importance.
Two readings per year is a reasonable starting point but more may be warranted, especially in locations where the arresters are exposed to high lightning activity and/or heavy atmospheric pollution.
• Specifically in advance of the designated lighting season and thereafter following periods with bad weather conditions.
• After special fault conditions causing flashover in the network or TOV’s of high amplitude and/or long duration.
Readings must be made more often and with short regular time intervals if the intention is to correlate the EXCOUNT-II data with other external measurements and recordings - lightning activity meters, SCADA, etc.