| CONTROL |
CONTROL | POINT |
CURVE | (Approx Deg) |
| AT 50% RH |
A | 73 |
B | 68 |
C | 63 |
D | 58 |
RH — Relative Humidity
Fig. 24 — Psychrometric Chart for Solid-State
Enthalpy Control
B. Differential Enthalpy Control
NOTE: The accessory
1.Remove and discard the
economizer control module (between terminals SR and +). See Fig. 18.
2.Disconnect black wire from economizer control mod-
ule terminal SO and blue wire from the OAT (outdoor- air thermostat).
3.Remove OAT and black wire assembly containing the
4.Mount the
5.Reconnect the blue wire removed in Step 2 to the enthalpy sensor terminal +.
6.Cut the violet wire provided to desired length and terminate with
7.Mount the second enthalpy sensor in the
8.Route the blue wire (provided) from terminal + on the
9.Route the violet wire (provided) from terminal S on the
10.Turn changeover set point dial clockwise past the “D” setting, or the control will not operate on a differen- tial. See Fig. 18.
11. Reinstall economizer hood if removed.
IMPORTANT: Be sure all seal strips and RTV sealant are intact. A watertight seal to inside of unit must be maintained.
XI. STEP 11 — INSTALL ALL ACCESSORIES
After all the
A.Motormaster® I Control Installation (581A155 and 180 Only)
Install
Wind baffles must be
CAUTION: To avoid damage to the refrigerant coils and electrical components, use recommended screw sizes only. Use care when drilling holes.
Install Motormaster I Controls
Only one Motormaster I control is required per unit. The Motormaster I control must be used in conjunction with the Accessory 0° F Low Ambient Kit (purchased separately). The Motormaster I device controls outdoor fan no. 1 while out- door fans no. 2 and 3 are sequenced off by the Accessory 0° F Low Ambient Kit.
Accessory 0° F Low Ambient Kit — Install the Accessory 0° F Low Ambient Kit per instruction supplied with accessory.
NOTE: Dimensions in ( ) are in mm.