Input Signal = 10 mA
°C Reset = (10 mA x 5.0 °C) = 2.5 °C Reset
20
New Setpoint = 50.0 °C - 2.5 °C = 47.5 °C
15.5.4 4-20 mA Remote Signal
Jumper JP on the I/O board must be set to 20 mA.
To calculate the hot liquid setpoint for values between
4 mA and 20 mA use the following formula:
Setpoint = Local hot Liquid Setpoint - °C Reset
°C Reset = ((mA signal - 4) x *Max Reset Value)
16
Example:
Local Hot Liquid Setpoint = 45.0 °C
*Max Reset Value = 5.0 °C
Input Signal = 12 mA
°C Reset = ((12 mA - 4 mA) x 5.0 °C) = 2.5 °C Reset
16
Setpoint = 45.0 °C - 2.5 °C = 42.5 °C
* Max Reset Value is the 'Max EMS-PWM Remote
Temp. Reset' setpoint value described in the
programming section under Cooling Setpoints.
Programmable values are from 1.11 °C to 11.11°C).
15.6 EMS-PWM Remote Temperature Reset
The EMS-PWM feature is not normally available. If the
message REMOTE TEMP RESET INPUT is visible
under the OPTION key even when set to DISABLED the
EMS-PWM feature is disabled. Contact Johnson
Controls York Product service if you require this feature.
If enabled this feature will work even when the Option
Local/Remote mode is set to Local. This input is not
active if an ISN, Bacnet or Modbus is connected, Option
Local/Remote is set to Remote and the ISN is not
handing back control to the panel by sending 99 on ISN
page 05.
The EMS-PWM remote temperature reset value at
terminals 13 - 20 on -XTBC1, will reset the hot liquid
'SETPOINT' based on the length of time the contacts
remain closed. The maximum temperature reset
allowed is achieved with a contact closure of 11
seconds. One second is the shortest time allowed and
causes the hot liquid 'SETPOINT' to revert back to the
local programmed value.
The reset value is always taken away from to the hot
liquid SETPOINT', meaning that this function never
raises the hot liquid 'SETPOINT' above the locally
programmed value, it can only reset to a lower value.
The microprocessor board must be refreshed between
30 seconds and 30 minutes. Any contact closure
occurring sooner than 30 seconds will be ignored. If
more than 30 minutes elapse before the next contact
closure, the setpoint will revert back to the locally
programmed value.
The new hot liquid 'SETPOINT' is calculated:
'SETPOINT' = hot liquid 'SETPOINT' - °'RESET'
°'RESET' = (Contact Closure - 1) x (*Max. Reset Value)
10
Example:
Local hot Liquid Setpoint = 50.0°C.
*Max Reset Value = 10.0°C
Contact Closure Time = 6 Seconds.
(6 sec - 1) * (10.0°C/10) = 5.0°C
Reset 'SETPOINT' = 50.0°C - 5.0°C = 45°C
This can be viewed by pressing the 'SETPOINTS'
keythree times.
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Form 201.26.OI1(11/09)
