Communication Power Supply; Requirements - Hitachi HIDIC EH-150 Applications Manual

Chapter 12 Communication Power Supply

12.1 Requirements

1. Use 24 V DC as communication power supply.
2. The power must always be supplied via the trunk line.
3. The maximum current at the trunk line is 8A with the thick cable, and 3A with the thin cable.
4. Basically, one communication power supply is required per one network. However, it is possible to supply
power from two or more communication power supplies to one network if the power supply specification
cannot be satisfied by one communication power supply.
5. An error may occur in each device if the communication power supply is turned off during the operation
without turning the modules off beforehand.
6. The maximum current capacity of a drop line becomes smaller as the length of a drop line becomes longer.
Obtain the allowable current capacity Ic of a drop line from the following formula:
Ic = 4.57/L
(L: length of the drop line (m))
The following table is the power specification to recommend in DeviceNet.
Item
Initial Tolerance
Line Regulation
Load Regulation
Temperature Coefficient
Output Ripple
Load Capacitance Capability
Temperature Range
Inrush Current Limit
Over Voltage Protection
Over Current Protection
Turn-on Time (with full load)
Turn-on Overshoot
Stability
Isolation
Output Voltage
Output current
Surge current capability
Table 12.1 DeviceNet power supply specification
Specification
24 V DC +/- 1% or adjustable to 0.2 %
0.3 % max
0.3 % max
0.03 % ore deg C max
250 mV p-p
7000 uF max
Operating
Non-operating
* De-rating acceptable for 60 °C operation
less than 65 A peak
yes
yes ( current limit 125 % max )
250 ms max / 5 % of final value
0.2 % max
0 to 100 % load ( all conditions )
output isolated from AC and Chassis fround
24 V +/- 1 %
up to 16 A continous
10 % reserve capability
Chapter 12 Communication Power Supply
* 0 to 60 °C
-40 to 85 °C
12-1