Temperature Effect; Powering The Link/Repeater - GarettCom 5843HRT User Manual

Figure 10 shows the maximum number of repeats possible if 70% of the original pulse width
is required by any IED in the loop. The acceptable percentage of the original pulse width is
due to the requirements of the IED's. If more of the original pulse width is necessary or less
is allowable, then the number found in Figure 10 can be modified. Table 2 shows the
factors to be used to correct the number of repeats found in Figure 10 for such cases.
3.3.3

Temperature Effect

At peak operating temperature above 65°C, the maximum number of repeats should be de-
rated by 20%. At higher temperatures, the distortion caused by each repeat increases,
causing the maximum number of possible repeaters to go down.
EXAMPLE:
Peak temperature of the system will be 70°C
Running at 9600 bps
60% of original pulse width possible
3.4

POWERING THE LINK/REPEATER

3.4.1 Model 5843HRT
Model 5843HRT may be powered through pin 9 on the D-connector or by means of the 3.5
mm female connector located between its two optical ports. The unit has an input voltage
range of 9 to 15 Vdc and requires a maximum of 250 mA (340mA for the 5843SHRT) over
the entire operating temperature range. DYMEC's Model 4310S ac to dc power adapter is
designed specifically for this purpose. It connects directly into a normal 110 volt power
receptacle and has an operating temperature range of -0°C to +70°C.
3.4.2 Model 5844HRT
Model 5844HRT is designed with an internal universal regulated power supply for envi-
ronments where unregulated ac or dc voltages are available. It accepts ac voltages in a
range of 90 to 250 volts, 50 or 60 hertz, or dc voltages in a range of 90 to 250 volts. These
power sources must be capable of supplying 35 mA (50mA for the 5844SHRT) over the
entire operating range. It is also possible to power the Model 5844HRT through pin 9 on the
D-connector.
Table 2
% of Original Pulse
80%
60%
50%
initial: 100 repeats (from Figure 10)
less: 20% de-rate for 70°C
times: 1.33 for 60% pulse width
equals: 100 x 0.8 x 1.33 = 106 repeats
3-4
Models 5843, 5844, 5843S and 5844S
Multiply Factor
.67
1.33
1.67
RS-232 or TTL