Johnson Controls York VCH 20A, Technical Information

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64
Economiser
These instructions provide the necessary information for cor-
rect installation, at the job site, of the economiser dampers.
The economiser is located in the return section of the VIR
indoor unit (see Fig. 1).
The control board, cables and all material necessary for
installation are supplied with this accessory.
Technical specifications
This accessory includes the return and outdoor air dampers
and a drive motor with a return spring modulated by tempera-
ture control (enthalpy probes optional).
This accessory is comprised of:
- Damper assembly, with motor, for outdoor air.
- Damper assembly, with motor, for return air.
- Control board, plastic partitions and protecting cover.
- Temperature sensors for return and outdoor air and air
impulsion.
- Wiring assembly, ready for connection to unit wiring.
- A set of panels and supports.
- Screws and wall hole guides for assembly.
Installation
Turn main power supply to the unit off by means of main
switch Q1.
Prior to installing the economiser it is indispensable to know
how the outdoor air duct will be connected at the job site.
There are two possibilities: Top or bottom duct (Figs. 1 and
2).
Install the economiser as follows:
1. Assembly of outdoor air intake by means of top duct
(standard configuration). The outdoor air damper will be at
the top, and the economiser cabinet should be confronted
with the frame of the corresponding VIR unit filter. To
fasten, use the screws, nuts and washers supplied. The
panels must be removed first so to insert the screws.
2. Assembly of the outdoor air intake at the bottom duct.
Remove the side supports and fit them on the opposite
side. Then turn the unit fully around, as shown in the
figure. For coupling to the VIR indoor unit, proceed as in
the standard configuration.
3. Position of the of dampers. The stand-by position of the
dampers is: outdoor air closed and return air, open. Check
the position of the dampers.
4. Connection of the economiser control board wiring.
Connect the economiser hose cables as shown on the
wiring diagram: power supply cables (J17, 580 and 581),
accessory communication cable (J16, 700), motor cables
(R-red, C-black, 0-10V-grey), return probe (J13-black),
outdoor probe (J3-white) and impulse probe (J6-yel-
low).
5. Assembly of return, outdoor and impulse air temperature
sensors. Depending upon the assembly of the dampers,
it is advisable to install the sensor supports as well as the
return (B15), outdoor (B17) and impulse (B16) air tem-
perature sensors at a minimum distance of at least 1 m.
from the mouth of the duct connected to the machine.
6. Assembly of enthalpy probe, Ref. C7400A (option not ap-
plicable). The enthalpy probes are an optional accessory
that cannot be installed with the VIR unit economiser.
7. J19, J20 and ENTALP jumper selection.
- J19 jumper: Open by default, selects economiser opera-
tion. If closed, selects motor-driven damper operation.
- J20 jumper: Open by default, selects outdoor damper
closed with high temperature/smoke alarm. If closed, se-
lects outdoor damper open with high temperature/smoke
alarm.
- ENTALP jumper, S2: Open by default, selects operation
without enthalpy probes.
8. Configuration of economiser control board and adjustment
of minimum opening.
Once this accessory is fitted, along with the necessary
elements, the unit is powered on once again.
Make sure the green LED (V1) of the economiser control
board (A4) is on permanently.
To carry out a search and configuration of accessories,
press the test button on the Yklon board (A1) located on
the outdoor machine for over three seconds, until the red
LED goes on. Once this search and configuration proc-
ess begins, the red LED goes on and stays on until this
operation is over. Once it goes off, make sure the green
LED (V1) of the economiser board is flashing to indicate
the accessory has been configured.
A potentiometer, P1, on the economiser board allows
modulating the damper manually to check its operation.
The damper will go back to its operating position after
30 seconds.
As long as the indoor fan is on, the damper will be open
proportionally to renew air circulation. Factory set default
value is 10%. This minimum percentage can be set by
means of potentiometer P1, or through the communication
network. To set it with the potentiometer, set the minimum
value until the minimum opening is reached, and then
press configuration button SW1 for 3 seconds to store
this value.
9. Air quality probe (optional).
The air quality probe is equipped with a VOC (volatile
organic compounds) sensor that compares the VOC
concentration in the air with the sensor set point. If this
concentration is greater, the probe activates outlet Y1 by
means of a relay.
The 230 VAC outlet signal between Y1 and N connects
to the 230 VAC to 5VDC conversion board. This board is
to be fitted next to the economiser control board and the
5 VDC signal cable should be connected to J18 on the
economiser board.
If the room thermostat temperature set point is satisfied
and there is a call for air quality, the damper opens to
minimum programmed renovation and the indoor fan turns
on. Then the damper opening is increased in accordance
with the maximum (30° C) and minimum (12° C) impulse
temperatures. If the air quality call signal disappears, or
if the thermostat calls for air quality, or if the thermostat