York MILLENNIUM YCUL0045SC, Installation Operation & Maintenance

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YORK INTERNATIONAL
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If a 4 - 20 mA signal is available, it is applied to termi-
nals A+ and A- and jumpers are applied to JU5 and
JU3 on the reset board. The mA signal is conditioned to
a 1-11 second PWM output. The PWM output is then
supplied to the PWM input on the microboard at CTB1
terminals 13 - 20. To calculate the discharge air tem-
perature setpoint for values between 4 mA and 20 mA
use the following formula:
Setpoint =
discharge air temperature se °reset
° Reset =
(mA signal - 4) x (*Max Reset Value)
16
Example:
Local Discharge Air Temperature Setpoint = 55° (12.8°C)
*Max Reset Value = 10°F (5.6°C)
Input Signal = 12 mA
(English)
° Reset =
8 mA x 10°F
= 5°F reset
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Setpoint = 55°F + 5°F = 60°F
FIG. 12 – FIELD AND FACTORY ELECTRICAL CONNECTIONS
OPTIONAL REMOTE TEMPERATURE RESET BOARD
(Metric)
° Reset = 8 mA x 5.6°C = 2.8°C reset
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Setpoint = 12.8 °C + 2.8n °C = 15.6 °C
If the Contact Closure input is used, the connections
are made to terminals C and D and only jumper JUI
must be in place on the reset board. This input is used
when a
single reset value is needed. When the contacts
are closed, the remote temperature reset board will con-
vert this contact closure to a PWM signal that is applied
to CTB1 terminals 13 - 20.
To set the PWM output, the contacts must be closed on
inputs C - D, and potentiometer R11 (located on the front
edge of the PC board) is adjusted to 10 VDC as mea-
sured at TP3 to terminal 10 on the circuit board. The
reset value will be the “Max EMS-PWM Remote Temp.
Reset” setpoint value programmed in the SETPOINTS
section under the Cooling Setpoints key.
The coil of any added relay used for re-
set must be suppressed to prevent pos-
sible component damage. Use YORK
P/N 031-00808-000 suppressor.
LD03875
035-15961-000
+
–
Unit Controls
240-24 Volt ratio transformer used to derive nominal 12-Volt output from
a 120-Volt supply.
* Max Reset Value is the “Max EMS-PWM Remote Temp. Reset” setpoint values described in the programming section under Cooling
Setpoints. Programmable values are from 2°F to 40°F (1.11°C to 11.11°C).