COVER MY SERIES – User Manual
COMEX S.A.
8
personnel with appropriate knowledge and authorizations should have knowledge of the
standards and norms in force on the local market regarding the type and cross-sections of
cables, their arrangement and load capacity. It is recommended to use LgY or OpD hoses.
2.5.1.
UPS input power
The UPS should be supplied from an electrical switchboard equipped with an appropriate
protection device, matched to the maximum power of the system, and flexible cables with an
appropriate current-carrying capacity matched to the applied protection.
If installation of RCDs on the UPS power supply is required, remember 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 0.3 - 1A.
The RCD must be sensitive to unidirectional DC current pulses, and insensitive to transient
current pulses, as shown in the figure below:
Figure 2.4. RCD marking
2.5.2.
Battery circuit protection
The battery required for correct operation of the power supply consists of 30 - 40 12 V batteries
connected in series. A 3-wire installation is required with a center neutral point taken from the
central connection between battery 20 and 21, in the case of a string 40 of batteries. The battery
circuit must be protected with an appropriate fuse, selected according to the power of the UPS.
The detailed battery installation drawing is shown below:
Figure 2.5. Diagram of connecting 40 batteries in series with the central point
MY series UPS are equipped with an advanced discontinuous charging system, characterized by
two charging levels and a rest period. The batteries are charged with a constant current value
and a constant voltage value to obtain the maximum battery capacity. After the charging
process, which usually takes up to 2 days, the so-called “resting mode” period consisting in
switching off the charging system. Disconnecting the charger from fully charged batteries
eliminates the process of their continuous recharging, which in long operation may lead to
drying out of the electrolyte and accelerated battery wear. The period of restoration depends
on the speed of self-discharge of the accumulator batteries over time and the conditions in the
room where they are used. As standard, in the absence of power outages, the charging system
is activated after 14 days of the rest period, which is the most optimal value from the point of
view of battery life and ensuring the required autonomy.