4
Unpacking:
Before unpacking your unit, examine the shipping carton for damage. If there is any
obvious damage, report it immediately to the dealer or carrier. If no damage is found, unpack the unit
and inspect it for shipping damage. Again, in case of any damage, report it directly to the dealer or the
carrier.
Environment:
The MESTA UPS is designed to be used in an environment with a temperature range of
0 to 40 degrees C and relative humidity of 0 to 95%, without condensation. The site should not be
excessively dusty or dirty. If the site is excessively dusty or dirty, contact the manufacturer about the
possibility of adding external air filters to the front of the unit to filter the intake air to the UPS. If
excessive dirt is allowed to enter the unit, the fans and/or heat sink fins could become clogged with dirt,
thus requiring excessive maintenance. Clearances should be provided to the top, front and back of the
unit so as not to block air inlets and outlets, or rear mounted connectors. Also, keep the top of the unit
clear of objects.
Customer-Supplied Wiring
External on-site wiring to supply the UPS must be
provided by the customer (See Figure 3). If a Wye
service feed is available having the same voltage
characteristics as the UPS (e.g. 208/120Y for most
systems), a service feed breaker (see Table 1 for
ratings) must be installed to protect the internal UPS
transfer switch when the UPS is in the "Bypass” mode of
operation. If some other voltage configuration, such as a
delta feed and/or different voltage, is only available, an
isolation transformer (such as one supplied by Mesta
Electronics shown in Figure 2) along with a service feed
breaker is required. Refer to Table 1 for wire, breaker
and transformer ratings for alternative configurations having either 480 or 240 volt service feed
available. View A of Figure 3 shows wiring for such an arrangement.
Figure 3 UPS External Wiring
3 PHASE
208/120Y
SERVICE
X
Y
Z
NEUTRAL
GROUND
SERVICE FEED
BREAKER
(customer supplied)
X
Y
Z
NEUTRAL
3 PHASE
208/120Y
LOAD DISTRIBUTION
PANEL
(customer supplied)
B+ B-
X Y Z W
X Y Z W
OUTPUT
INPUT
TERMINAL BLOCKS
TO EXTERNAL
BATTERY
BREAKER
(optional)
UNINTERRUPTIBLE
POWER SYSTEM
CABINET
EXTERNAL BATTERY
(optional)
B+ B-
IMPORTANT:
X phase leads Y by 120
Y phase leads Z by 120
o
o
GROUND
NOTES:
1. Grounding of enclosures
can be achieved through
conduit approved for such
application and/or wires
connected to points
marked "GND".
OR OPTIONAL
BREAKER/ISOLATION
TRANSFORMER
(SEE VIEW A)
(208/120Y OUTPUT)
ISOLATION TRANSFORMER
DEDICATED
GROUND
Z
Y
X
SERVICE
3 PHASE
X
Y
Z
W
VIEW A:
BREAKER/ISOLATION TRANSFORMER
GROUND
TO
UNINTERRUPTIBLE
POWER SYSTEM
INPUT
GND
GND
GND
GND
NEUTRAL
GROUND
Figure 2 Isolation Transformer
