Specifications

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EATON Powerware Series Product Catalogue
Maximised energy efficiency
VMMS optimally employs uninterruptible power modules (UPMs)
in the UPS to achieve higher efficiencies in double conversion
mode in order to maximise the percentage load level of the
remaining active UPMs by switching UPMs that are not needed to
ready state*.
This is calculated according to the UPMs’ VMMS load threshold
– 80% by default – and the system configuration (redundancy
requirements). This results in maximised energy savings.
VMMS is only possible thanks to Eaton 9395 UPS modularity.
VMMS–can also be applied in multimodule single-UPS systems.
*In “ready state”, the UPM rectifies the DC-link, generates logic
level PWM (Pulse Width Modulation) signals and filters EMI and
lightning spikes.
No compromise on reliability
When a disturbance or load increase occurs on a critical bus, all
all the UPMs in ready state are able to react quickly, immediately
switching back to double conversion mode connecting the existing
PWM signals to the IGBT gates.
In VMMS, all UPMs will switch to double conversion if:
• the output voltage fluctuates by more than 3% for any reason
• any UPM reaches its current limit or discharges its battery
• battery recharge is necessary.
Once the above conditions are resolved, the system switches back
to VMMS, after a customer-preset time delay (1 to 60 hours): once
the load stabilises, Eaton proprietary design and algorithms allow
the system to determine which UPMs to switch back to ready
state to maximise efficiency according to the new operating condi-
tions.
Extensive configurability
Customers can decide how to configure their system, establishing
the number of redundant UPMs and the max percentage load level
per UPM allowed in VMMS setting other UPM’s in ready state.
VMMS can be used in all multi-module (multiple-UPM) 9395
systems:
• Single 9395 units from 550kVA to 1100kVA
• Distributed parallel systems (Xx550, Xx825, Xx1100)
• SBM system
Existing installations can also be upgraded with VMMS capability:
• VMMS maintains redundancy and achieves higher efficiency
by intelligently controlling the load levels of UPMs
• Number of redundant UPMs can be selected
(N+0, N+1, N+2, N+X)
• UPMs in ready state can be used as redundant units (N+0)
UPS configuration Without VMMS VMMS on N + 1 redundancy VMMS on N + 0 redundancy
Efficiency @ 440 kVA load 91.2% 92.8% 94.3%
UPS energy savings
Used as reference for savings
calculation
56 MWh / year 108 MWh / year
Additional benefits
&
comments
3 Industry-leading UPS
efficiency in double conversion
3 Additional energy savings from reduced cooling in VMMS
(typically 30-40% on top of UPS energy savings)
3 UPMs in VMMS ready state available for redundancy
A Feed
220 kVA
B Feed
220 kVA
A Feed
220 kVA
B Feed
220 kVA
A Feed
220 kVA
B Feed
220 kVA
Data centre with dual-corded servers, 825 (3x275) kVA UPS on A and B side – 440 kVA load
VMMS
Parallel Eaton 9395 – 825 kVA modular
UPS and VMMS
UPS1 UPS2 UPS3
Full system efficiency is
automatically optimised
according to the load level
L
O
A
D
Variable Module Management System (VMMS)