23
In North America, there are only two recognized supply voltages: 208
VAC (most commonly used in industrial, commercial, and office areas); and 240
VAC (most commonly used in residential areas). 120 VAC can be derived from
both 208 and 240 VAC services.
NOTE: The terms 220 VAC and 230 VAC are actually local terminology,
referring to 240 VAC service.
IMPORTANT: This unit complies with NEC/CEC for center tapped neutral
bond to ground.
VOLTAGE POTENTIAL
UPS units equipped for 208 VAC output operation have a 208 VAC potential
between L1 and L2. In comparison, when the UPS is wired for 240 VAC output, a
120 VAC potential appears
between L2 and Neutral, and L1 and Neutral. For further
information, contact Alpha for assistance.
The transformer used in the CFR UPS is equipped with an additional tap
(L1 to N) for 120 VAC operation. This provides a dual output voltage potential of
208 VAC and 120 VAC.
NOTE: In this configuration, the voltage potential between L2 (208 VAC)
and Neutral is only
88 VAC. Refer to Fig. 14.
LOAD SHARING
If several pieces of equipment are connected to the 120 V output of the
CFR (either to the output receptacle or terminal block), care must be taken to
ensure that the total power drawn does not exceed the maximum rating of the unit.
For Terminal block output, wherever possible, connect all 120V loads to L1 (not
L2). If 120 V loads are connected to L2, do not exceed the current listed in Table
3.4.1.
3.4
208 VAC vs 240 VAC (60 Hz) Configurations
3. INSTALLATION
Table 3.4.1
Model
Maximum current on L2
CFR 1500
7.2A
CFR 1500RM
7.2A
50
503
504
5. RS-232 TERMINAL COMMUNICATION
5.9
User Parameters
,
continued
505
506
Also displayed on line 502 is the current status of the output:
“off”
No shutdown is scheduled.
“shutting down in hh:mm:ss”
Indicates the time remaining until
shutdown.
“shutdown in progress”
No output.
Activating this command requires the USER SECURITY CODE.
Cancel Output Shutdown
This command cancels any pending or current UPS output shutdown.
This command requires the USER SECURITY CODE.
Recover Output Shutdown Only When AC Line Restored (xxx)
xxx=“Yes” or “No”, (Default value is “Yes”)
This command determines when the CFR restores output power after
a output shutdown. If this option is set to “Yes”, the UPS restores output when
the input AC line is restored. Note that the output is guaranteed to be off for
the
“Output Shutdown Duration” period. During this period, the CFR will not
activate the output, even if AC line is restored. However, if this option is set to
“No”, then the CFR activates its output as soon as the
“Output Shutdown
Duration” has expired. Thus, the CFR may even restore output in the inverter
mode. Changing this option requires the USER SECURITY CODE.
Set Output Shutdown Delay (HH:MM:SS= hh:mm:ss)
This command sets the “output shutdown delay” period. After the
CFR receives an output shutdown command, it will wait for this period before
switching off the output.
hh:mm:ss - hh is hours; mm is minutes; ss is seconds. Entering the
seconds is optional, (i.e., HH:MM format is also acceptable). The factory
default setting for this value is 00:00:00 which causes the CFR to immediately
shutdown when a shutdown command is set. If the CFR is set to start shutdown
when delay is set (menu item 501 is set to “Yes”), then it also acts as a
shutdown command, and the count down for shutting down the unit starts
immediately (there is no need to issue a 502 command). This feature requires
the USER SECURITY CODE for activation.
Set Output Shutdown Duration (HH:MM:SS= hh:mm:ss)
This command sets the “Output Shutdown Duration” which is the
guaranteed down time after an output shutdown.
hh:mm:ss - hh is hours; mm is minutes; ss is seconds. Entering the
seconds is optional, (i.e. HH:MM format is also acceptable). The factory
default setting for this value is 00:00:05 which causes the CFR to remain in
shutdown for a minimum of 5 seconds. The CFR may restore output
immediately when this duration is expired, or may wait for the AC line to be
restored (depending on the setting of menu item 504). This feature requires
the USER SECURITY CODE for activation.
