Little Glass House User Manual

8
OPERATION
ENVIRONMENTAL CONTROL MODULE
(ECM) & UNINTERRUPTIBLE AIR SUPPLY™
(UAS)
For integrated/matched models, the
Environmental Control Module is normally sized
to match the capacity of the UPS module and
heat transmitted into the Little Glass House™.
The module is located at the bottom of the
enclosure. Internal air is conditioned and
circulated within the enclosure. Outside
(ambient) air is used to remove heat from the
enclosure through the air cooled condenser. The
outside air is drawn through a louver and filter at
the bottom front of the unit and is discharged at
the rear (near the bottom).
The lighted ON/OFF switch is located inside the
front door, on the left side of the electrical panel
on 60 Hz models. For 50 Hz models, use circuit
breaker “B” of electrical service assembly for
ECM On/Off.
At rated maximum ambient conditions, the
temperature inside the enclosure will be from
70° to 95°F (21 to 35°C), depending on the
electronics load. The two speed fans are factory
set to operate at the lower speed for quiet
operation when the outside air entering the
condenser is below 80°F (27°C). The
compressor in the Environmental Control
Module will turn off if the internal cabinet
temperature goes below 65°F (18°C).
The hot gas bypass valve is factory set so the
compressor will operate nearly continuously for
maximum compressor life. This valve
modulates automatically to match compressor
capacity to the present load. Consult factory if
adjustment is desired.
In UAS systems, during an enclosure high
temperature condition (100°F - 38°C) a separate
Back-up Cooling Fan operated on UPS battery
power (if included) will use filtered ambient air to
cool the enclosure. This would occur only
during a power failure or an Environmental
Control Module failure. To annunciate a high
temp condition, an alarm beeper sounds and the
alarm contact closes (press Alarm Silence
switch to turn off beeper). Outside air is drawn
through a louver and filter at the bottom front of
the unit and is discharged at the rear (near the
top).
FORCED AIR COOLING (FAC)
Forced Air Cooling can be provided by a single
fan (nominally rated at 190 CFM - 323 CMH), or
by dual fans (nominally rated at 360 CFM - 611
CMH). The two-speed fans are activated by a
temperature switch. Ambient air is drawn
through the filter at the bottom front of the unit,
and discharged at the top rear.
The ON/OFF control switch is located inside
the front door, on the left side. The same
control box includes the temperature switch
factory set at 80°F (27°C), which measures
air entering the unit. If the entering air
temperature goes above 80°F (27°C), the fan
speed switches from low to high.
UNINTERRUPTIBLE POWER SUPPLY (UPS)
The Little Glass House may be supplied with
one of several Liebert UPS units, or with no
UPS. For integrated/matched models, the UPS
and ECM are normally sized with matched
capacities. A larger UPS can be supplied for
more battery time, but the connected electronics
load should not exceed the ECM rating.
For LGH models supplied with a UPS, refer to
the separate UPS manual for operation and
specifications.
SITENET® INTEGRATOR®
Refer to the Integrator Electrical Connection
Diagram on page 21 for specifics regarding
installation.
The SiteNet Integrator is a separate rackmount
unit that communicates status of the UPS and
LGH. The option consists of a SiteNet Integrator
module that is typically mounted in the top of the
LGH cabinet.
The SiteNet Integrator is powered by one or two
externally mounted power supplies. One is
standard, the second is optional. These power
supplies provide the 9VDC required to power the
Integrator module. One supply will be plugged
into the UPS or the UPS outlet strip located in
the rear hinge side of the cabinet. The output
cable is plugged into the SiteNet Integrator
Power Supply Main input receptacle/socket. The
(optional) second supply will be plugged into the
electrical service power inlet in the lower rear of
the LGH cabinet. The supply's output cable is
plugged into the SiteNet Integrator Power
Supply Aux input receptacle/socket.