COVER serii NHS – User Manual
COMEX S.A.
9
force on the local market regarding the type and cross-sections of cables, their arrangement and
loadability. It is recommended to use flexible LgY or OpD type hoses.
2.5.1. UPS input power supply
The UPS should be supplied from an electrical switchgear equipped with a suitable security device
selected for the maximum system power, and flexible hoses with appropriate current carrying capacity
matched to the protection used.
If it is required to install RCDs on the UPS, please note that these devices should:
be sensitive to unidirectional DC current pulses (class A)
not be sensitive to transient current pulses
have adjustable sensitivity in the range of 0.3 - 1.0 A.
The RCD must be sensitive to unidirectional DC current pulses, and insensitive to transient current
pulses, as shown in the figure below:
Figure 2-5 Marking the RCD
2.5.2. Battery circuit protection
The battery required for correct operation of the power supply consists of 36 - 44 12V batteries
connected in series. A 3-wire installation with a center neutral point, taken from the central connection
between the 20 and 21 batteries (for 40 items) is required. The battery circuit must be protected by an
appropriate fuse, selected according to the UPS capacity and the number of batteries.
A detailed drawing of the battery installation is shown below:
Figure 2-6 Diagram of connecting in series 40 pcs of battery with a central neutral point