Honeywell Design and Application Technical Reference Manual page 202

Section 17 - Retrofit and Upgrades
The M7285A1045 is powered with transformer connected to T1 and T2 (L1 and L2 as shown
above). The MAT internal to the W859 is replaced with a C7250A1001 sensor connected to the
MAT on the W7220. Add a C7400S1000 S-Bus sensor for the outdoor air changeover. Use
separate transformers for the motor and for W7220. The W7220 must be earth grounded.
Old Sensor Description
C7046A Discharge Air
C7150B Mixed Air
C7400 Solid State Enthalpy
C7660 Solid State Dry Bulb
There is no longer a need for Minimum Position and Changeover Curve (A, B, C, D)
potentiometers. The changeover curve boundaries and minimum position are set using the LCD
display menu item "Setpoints" and the 4 buttons on JADE
For programming JADE
63-8594-02 Honeywell Economizers
refer to the Installation Instructions (62-0331).
TM
New Sensor
C7400S1000
C7250A1001
C7400S1000
C7250A1001
.
TM
196