Hydronic heat sequence of operation, Hydronic heat freeze stat, Ventilation – York ECO2 YPAL 050 User Manual

Page 89

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89

JOHNSON CONTROLS

FORM 100.50-NOM6 (1207)

5

HYDRONIC HEAT

The following parameters must be programmed to use
Hydronic Heat:

“HEATING MODE ENABLED FOR OPERATION”
must be enabled using Parameter 54 under the
PROGRAM key of the Simplicity Elite control board
or under the HEATING SETUP tab in the Simplicity
PC software package.

“HYDRONIC HEATING ENABLED” must be enabled
using Parameter 18 under the PROGRAM key of the
Simplicity Elite control board or under the HEATING
SETUP tab in the Simplicity PC software package.

“HYDRONIC HEATING STAGE #1 SUPPLY AIR
SETPOINT”
must be programmed using Parameter
19 under the PROGRAM key of the Simplicity Elite
control board or under the HEATING SETUP tab in
the Simplicity PC software package.

“HYDRONIC HEATING STAGE #2 SUPPLY AIR
SETPOINT”
must be programmed using Parameter
20 under the PROGRAM key of the Simplicity Elite
control board or under the HEATING SETUP tab in
the Simplicity PC software package.

Sequence of Operation

On Constant Volume units whenever there is a call for
the 1st stage of heating operation the Simplicity Elite
control will vary a 2 to 10 VDC output to the hydronic
valve to try and maintain the supply air temperature to
within +/- 1.0° F of the “HYDRONIC HEATING STAGE
#1 SUPPLY AIR SETPOINT”
. The output to the valve
can be found at terminal “HWV+” and “HWV-“ at
connector P14 on the Simplicity Elite control board.

On Constant Volume units whenever there is a call for
the 2nd stage of heating operation the Simplicity Elite
control will vary a 2 to 10 VDC output to the hydronic
valve to try and maintain the supply air temperature to
within +/- 1.0° F of the “HYDRONIC HEATING STAGE
#2 SUPPLY AIR SETPOINT”
.

On a VAV unit whenever there is a call for heat the
Simplicity Elite control will vary the 2 to 10 VDC output
to the hydronic valve to try and maintain the supply
air temperature to within ±1º F of the “HYDRONIC
HEATING STAGE #2 SUPPLYAIR SETPOINT”

The normal output to the valve is 2 VDC for 0% opening
of the hydronic valve and 10 VDC for 100% opening of
the hydronic valve. If the following is enabled:

“HYDRONIC HEAT ACTUATOR VALVE REVERSE
ACTING”
must be enabled using Parameter 21 under
the PROGRAM key of the Simplicity Elite control board
or under the HEATING SETUP tab in the Simplicity
PC software package.

Under this condition, the normal output to the valve is
10 VDC for 0% opening of the hydronic valve and 0
VDC for 100% opening of the hydronic valve.

HYDRONIC HEAT FREEZE STAT

All hydronic heat units are equipped with a freeze stat
that monitors the temperature of the return air. The
switch action is normally closed and opens when the
return air temperature is less the 40.0º F. The 24 VAC
signal to the freeze stat originates at terminal FSP on
the control board. The 24 VAC input from the freeze
stat enters the control at the FSI terminal.

When the freeze stat input is lost, the Simplicity Control
will send a 10 VDC signal to the valve (direct acting), 2
VDC (reverse acting) to open the valve. The valve will
continue to drive open for 5 minutes, even if the freeze
stat circuit remakes. If the freeze stat circuit closes and
the 5 minute timing has expired, the unit will return to
normal operation.

If the supply fan is operating and the outdoor damper
is open the Simplicity Control will close the damper
during the above sequence.

VENTILATION

The unit can be ordered / programmed for the following
ventilation options:

None.

Manual.

Fixed Minimum – Economizer option required.

Demand Ventilation – Economizer option re-

quired.

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