PHOTOCELL PLACEMENT
In applications where windows
are the primary source of
daylight, the LS-290C photocell
typically mounts on the ceiling
between the window and the
first row of fixtures. For skylight
applications, the photocell
mounts in the lightwell. T h e
photocell is aimed toward the
daylight. Maximum wire
distance from the controller to
the photocell is 250 feet.
You need a light merter to
measure light levels at task
a r e a s .
See the LS-290C Photocell
installation instructions for
information about placement,
mounting and testing.
LCO-203 INSTALLATION
1 . The LCO-203 controller mounts onto a DIN rail inside of an
electrical enclosure rated for the application. Ty p i c a l l y, a NEMA 1
rated enclosure such as the Watt Stopper LS-E8 is used. One
LCO-203 and one BT-203 can be mounted in an LS-E 8 .
2 . All wiring connected to the LCO-203 is low voltage. Low voltage
wiring must be separated from line voltage wiring. Low voltage
wiring must enter the enclosure through knockouts separate from
high voltage wiring.
• Switch and sensor wires terminate at the terminal strips on the
top rows (labeled A and B).
• Wire all devices to the LCO-203 before connecting it to the
power pack or making any adjustments or program changes.
See the Low Voltage Wiring section for information about wiring
each device.
• Use the quick connect cable supplied with the LCO-203 to
connect it to the BT-203 Power Pack.
Figure 3: Wiring terminal locations
Adjustments
The display and buttons on the face of the LCO-203 allow you to
make various system adjustments. The LCO-203 comes with two pre-
programmed applications. Each application has factory default
settings. Depending on the circumstances of your installation,
adjustments may not be necessary. See the Controller A d j u s t m e n t s
and Display section for details.
OPERATION
Automatic Control
When in Automatic mode, the LCO-203 turns the lights ON or OFF
based on the amount of daylight measured by the photocell. Based on
the settings that you program for each channel, the LCO-2 0 3
automatically calculates when the lights need to be turned ON.
On/Off Switching
The BT-203 provides ON/OFF switching based on the combined
requirements of daylighting, occupancy, time clock and manual control
inputs to the LCO-203. The BT-203 Power Pack has one normally
open relay for each channel. It is closed whenever the LCO-203
determines that the electric lights are required in the channel.
Daylight: The contacts open if the LCO-203 determines that there is
enough daylight in a channel and no electric light is needed. Program-
ming calculation relationships are shown in the graphs on page 3.
First, the channel’s Cutout point must be reached. The Cutout point
refers to the photocell light level required to provide enough light at the
c h a n n e l ’s task level to meet the programmed setpoint plus its
deadband percentage. The channel’s programmable
Off Delay
t i m e r
begins at the Cutout point. If the channel remains at or above the
Cutout point for the duration of the timer, the contact opens. See
Daylight Switching Calculations for more information.
Manual Off: When the wall switch is used, the contacts open to switch
all channels OFF when the I/O (On/OFF) button is pressed. Pressing
the I/O (On/Off) button again switches all channels ON.
Time Clock Interlock: When the LCO-203 receives a contact closure
at terminal B11, it signals an unoccupied period. The unoccupied
signal immediately opens the contacts for all three channel relays.
This turns lights OFF and holds them OFF until the Time Clock
Interlock contact opens.
End of Occupancy: When the occupancy sensor’s internal delay
expires and it removes the occupancy signal from the LCO’s terminal
A8, a one-minute delay timer starts. If there is no occupancy signal
when the delay expires, all channels turn OFF.
Manual Control
The LS-4C and LS-3C are optional wall switches that allow manual
override of all channels in unison. Once manually set, the lights
remain ON or OFF until the LCO-203 resumes Automatic operation.
To resume Automatic operation, press and release Au t o on the wall
switch. For another way to return the LCO-203 to Automatic, see L O W
V O LTA G E WIRING, Occupancy Sensor, on the next page.
Wall Switch (LS-4C or LS-3C)
The LED by the Au t o button lights when the LCO-203 is in automatic
mode. The LED by the I/O (On/Off) button lights when it is in manual
mode. Both LEDs are OFF when the LCO-203 is in programming/
diagnostic mode or when the time clock signal is present. For wiring,
see Figure 7 and 7a or the instructions that came with the switch.
Manual Operation
1 . Press and release the I/O (On/OFF) button on the switch.
2 . The Manual (I/O or On/Off) LED goes ON and all channels turn ON.
3 . Press and release the I/O (On/Off) button to toggle all channels ON
or OFF.
4 . Press and release the Auto button to exit Manual mode and return
to Automatic operation.
Figure 4: LS-4C (left side) and LS-3C(right side) Wall Switch controls
Figure 2: Photocell placement for a
window application
page 2