Page 18 of 23
17150 issue 17, October 2018
Vega DC Handbook
Module Output Voltage
Rated
Current
Power
Occupied
Slots
Secondary
Turns
Ampere
Turns
Max
Current
Limit
Setting for
Hazardous
Energy
Z7
(D3+D3)
8 - 16.5V
45.6A
752W
3
3/3
136.8/13
6.8
60A
>4V
Z18
(L1+L1)
4.5 - 5.5V
66.5A
366W
2
1/1
66.5/66.
5
87.5A
>2.7V
Note 1: Actual voltage and current output of an X module is dependent, and limited by, the ratings of the
modules from which it is fed. The ratings given above are additional rating limitations imposed by the X
module itself.
Note 2: The maximum power output of PSUs fitted with X modules is reduced from 450W by the following
power: 0.55 x (total X1 current) + 0.7 x (total X2 & X4 current) + 0.9 x (total X8 current).
Note 3: ‘Z’ modules are designed as follows:
Z2 = D1L+D1L
Z3 = E1+E1
Z4 = D1H+D1H
Z6 = E2+D1H
Z7 = D3+D3
Z18 = L1+L1
Additional module limitations:
E2 module fitted in slots 4/5 is limited to 55A.
C1Y module can only be fitted in slot 1.
F1 module is only permitted in slots 1 and 2.
F2 module may only be fitted in slots 1 and 2 and is limited to 75A for ambient temperatures of greater than
45°C.
For PSUs with three D modules fitted:
D1L & D1H in slots 2/3 is limited to 42A and in slots 4/5 is limited to 47A
D2 in slots 2/3 is limited to 40A
PSUs fitted with a W2 module are limited to a maximum ambient of 45°C.
All the above ratings and limitations apply to the individual modules from which a series or paralleled pair is
made.
Cooling for unit:
The following method must be used for determining the safe operation of PSUs.
The components listed in the following table must not exceed the temperatures given. To determine the
component temperatures the heating tests must be conducted in accordance with the requirements of the
applicable standards. Consideration should also be give to the requirements of other safety standards.
Test requirements include: PSU to be fitted in its end-use equipment and operated under the most adverse
conditions permitted in the end-use equipment handbook/specification and which will result in the highest
temperatures in the PSU. To determine the most adverse conditions consideration should be given to the
end use equipment maximum operating ambient, the PSU loading and input voltage, ventilation, end use
equipment orientation, the position of doors & covers, etc. Temperatures should be monitored using type K
fine wire thermocouples (secured with cyanoacrylate adhesive or similar) placed on the hottest part of the
component (out of any direct airflow) and the equipment should be run until all temperatures have stabilised.
