Specifications

February 2007
16-36
For more information visit: www.eaton.com CA08101001E
Transfer Switches
16
Transfer Switch Equipment
ATC-800 Closed Transition IQ Transfer Controller
ATC-800 Closed Transition
IQ Transfer Controller
Definitions
Closed Transition: Closed transition is
a feature that will temporarily parallel
two live sources in a make-before-break
scheme when performing a transfer.
The CTIQ (ATC-800) Transfer will close
the switching devices for both sources,
paralleling both sources, for a maximum
time of 100 milliseconds after the
sources are synchronized.
Open Transition/In-Phase Monitor:
In-Phase monitor is a feature that will
allow a transfer between two sources
only when the phase difference between
the two sources is near zero. This is an
open transition transfer that prevents
inrush currents from exceeding normal
starting currents in the case where
motor loads are being transferred.
Open Transition/Delayed with Load
Voltage Decay: Load voltage decay
transfer is a feature that, after opening
the switch for the original source, holds
in the neutral position until the voltage
on the load is less than 30% of rated
voltage. This is an open transition that
prevents inrush currents from exceeding
normal starting currents in the case
where motor loads are being transferred .
Operation
The Eaton CTIQ (ATC-800) Transfer
operates in the following modes to meet
most load management applications:
■ Loss of Normal Power
– Open Transition to
Alternate Source
■ Normal Power Restored
– Closed Transition back to
Normal Source
■ Peak Shave (Remote or Local)
– Closed Transition to and
from Alternate Source
■ Test (User Selectable)
– Load Transfer — Closed
Transition to and from
Alternate Source
– No-Load Transfer — Starts
Alternate Power Source and
Allows to Run Unloaded.
No Transfer Takes Place
ATC-800 Programming
and Options
Closed Transition Operation Modes
Feature Set 47C Closed/In-Phase/Load
Voltage Decay
CTIQ (ATC-800) Transfer controllers
equipped with Feature Set 47C execute
the following sequence of operations
upon receipt of a request for transfer:
the controller waits (for a pre-selected
time frame) for synchronization of
voltage and frequency. If achieved, a
closed transition transfer occurs. Fail-
ure to synchronize results in the con-
troller defaulting to an in-phase
monitor, open transition, mode of
operation. If the two sources fail to
achieve frequency synchronization
within the user selectable range, the
controller defaults to an open transi-
tion using a Load Voltage Decay
delayed transition.
Figure 16-18. Feature Set 47C Schematic
Table 16-41. Closed Transition/In-Phase Standard Features
Standard
Features
Customer
Adjustments
Closed Transition Frequency Difference (Hz)
Closed Transition Voltage Difference (Volts)
In-phase Transition Frequency Difference (Hz)
0.0 to 0.3 Hz
1 to 5%
0.0 to 0.3 Hz
Closed Transition Synchronization Timer
In-phase Transition Synchronization Timer
1 to 60 Minutes
1 to 60 Minutes
Request for Transfer
Alternate
Source
Available?
Sources
Synchronized
<Tmax
Both Sources
Still Available
Sources
Synchronized
<Tmax
Source 1 Open
<100 msec?
Close Source 2
Open Source 1
Detect Source 2 Closed
Good
Open Source 2
Alarm
Open Source 1
Close Source 2
Open Source 1
Load Voltage Decay
Close Source 2
End End End
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
Open Transition/
In-phase Monitor
Closed
Transition
Open
Transit
Delayed