eyePower PDU User Manual V1.0.docx
Page 2 of 6
Features:
Inlets / Outlets
Single or dual changeover inlets fitted with 16A powerCON. The unit is rated for 16A total, no need for a front panel
breaker which would affect fusing discrimination with the upstream 16A supply. Fourteen 10A IEC outlets are fitted,
together with dual supply, RS422/485, Ethernet and external sensor connections are on the rear panel.
Internal Distribution
eyePower Limited PDU do not rely on PCB tracks for power distribution, all units are hand wired with crimped
cables and soldered busbars. Installation fault currents can be surprisingly high, a 10A fuse can pass 30A for 30
seconds worst case. I2R heating of the distribution is then 9 times higher than normal running. PCBs can be
damaged in this time with failure possibly in the long term rather than immediate. Even for short circuits connected
to the unit, technical installations often have low loop impedances with high fault currents of kA that the distribution
must withstand before the fuse ruptures.
Fusing
Outlets are 10A rated to the unit maximum of 20A. Factory fit is 3.15A fuses which suits most loads and provides
clear discrimination between supply and outlet fusing. Customers can uprate fuses as required to maximum 10A.
Relay Switching
Relays are high quality, 20A rated with a tagged output wired direct to the 10A IEC outlets. Standard relays are
preferred, this latest unit reduces relay power consumption and heating by 70%. Relays hardly get warm using
PWM, a technique now favoured in the automotive industry to save energy.
Voltage Presence Detect
Supply voltage is detected after each fuse and after each relay, using a circuit which consumes 0.25W total for
over 30 measurements. Some other designs consume this much power for each presence detect and do not check
both fuse and relay.
Current Measurement
Current measurement is performed with high sensitivity current transformers. Unlike cheap, PCB mounted shunt
resistors there are no heating issues and reliability is maintained by simply passing the outlet cable through the
centre of the transformer rather than routing via PCB. With no direct connection to the supply, there are no issues
when measuring current throughout supply voltage disturbances. Currents from mA to 40A (70A peak) can be
monitored.
1-Wire
™
Sensors
Dallas/Maxim sensors can be connected. Sixteen are supported for local connection, allowing for temperature,
humidity and GPIs in addition to the standard four GPIs if required.
Macro Programs
eyePower PDU have at their core user programmable sequences for outlet and GPI interactions. This gives the
web interface access to complicated sequences to meet any requirement. Even the front panel switch can access
these macro routines, so the switch is extremely versatile. The unit can also redefine GPI and switch use according
to live requirements.
