CT5.241

C-Series

The unit is tested and approved for branch circuits up to 30A (U.S.A.) and 32A (IEC). An external protection is only

required, if the supplying branch has an ampacity greater than this. Check also local codes and local requirements. In

some countries local regulations might apply.

If an external fuse is necessary or utilized, minimum requirements need to be considered to avoid nuisance tripping of

the circuit breaker. A minimum value of 6A B- or 3A C-Characteristic breaker should be used

CT5.241 power supplies can be paralleled to increase the output power. This

power supply has no feature included which balances the load current

between the power supplies. Usually the power supply with the higher

adjusted output voltage draws current until it goes into current limitation. This

means no harm to this power supply as long as the ambient temperature stays

below 45°C. The CT5.241 can also be paralleled with power supplies from the

DIMENSION CT, QS or QT-series. The output voltages of all power supplies shall

be adjusted to the same value (±100mV). A fuse or diode on the output of

each unit is only required if more than three units are connected in parallel. If a fuse (or circuit breaker) is used, choose

one with approximately 150% of the rated output current of one power supply. Keep an installation clearance of

15mm (left / right) between two power supplies and avoid installing the power supplies on top of each other. Do not

use power supplies in parallel in mounting orientations other than the standard mounting orientation (input terminals

on the bottom and output terminals on top of the unit) or in any other condition where a derating of the output

current is required (e.g. altitude, above 60°C, …). Pay attention that leakage current, EMI, inrush current, harmonics

will increase when using multiple power supplies.

Unit A

AC

DC

Unit B

AC

DC

-

+

-

+

Load

+

-

Power supplies can be paralleled for redundancy to gain higher system availability. Redundant systems require a

certain amount of extra power to support the load in case one power supply unit fails. The simplest way is to put two

power supplies in parallel. This is called a 1+1 redundancy. In case one power supply unit fails, the other one is

automatically able to support the load current without any interruption. Redundant systems for a higher power

demand are usually built in a N+1 method. E.g. five power supplies, each rated for 5A are paralleled to build a 20A

redundant system. For N+1 redundancy the same restrictions apply as for increasing the output power, see also section

23.7.

Please note: This simple way to build a redundant system does not cover failures such as an internal short circuit in

the secondary side of the power supply. In such a case, the defect unit becomes a load for the other power supplies

and the output voltage can not be maintained any more. This can only be avoided by utilizing decoupling diodes

which are included in the decoupling module YRM2.DIODE.

Recommendations for building redundant power systems:

a)

Use separate input fuses for each power supply.

b)

Monitor the individual power supply units. A DC-ok lamp and a DC-ok contact is included in the redundancy

module YRM2.DIODE. This feature reports a faulty unit.

c)

1+1 Redundancy is allowed up to an ambient temperature of 60°C

N+1 Redundancy is allowed up to an ambient temperature of 45°C

d)

It is desirable to set the output voltages of all units to the same value (± 100mV) or leave it at the factory setting.

Jan. 2010 / Rev. 1.1 DS-CT5.241-EN

All parameters are specified at 24V, 5A, 400Vac, 25°C ambient and after a 5 minutes run-in time unless otherwise noted.

www.pulspower.com Phone +49 89 9278 0

Germany

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