Manual 2100-574
Page 2 of 23
CONTENTS
Economizer Failure Alarm .....................................16
Dirty Filter Alarm ....................................................16
2-Compressor Run Alarm ......................................16
Alarm Wiring ...........................................................16
2nd Stage Cooling Alarm .......................................17
Refrigerant pressure Alarms .................................17
Spyder Economizer Displays ................................17
Emergency Ventilation Sequence .........................17
programming Instructions .....................................20
Figures
— — — MD4000 Flow Chart ................................10
Figure 1 Controller Connections 1-Stage (H**A/L ....
Series) A/C w/ECONWMT Econ. .............14
Figure 2 Controller Connections 1-Stage (H**A/L ...
Series) A/C w/ ECONWMT Econ. & w/Alarm
Board & CB4000 Comm. Board .............15
— — — Alarm LED Display Board ........................16
Figure 3 Alarm Board Connections for Normally ......
Closed "NC" Open-On-Alarm Strategy ....18
Figure 4 Alarm Board Connections for Normally Open
"NO" Close-On-Alarm Strategy ................................19
— — — MD4000 Label .........................................21
Figure 5 Parts List Description Diagram ................22
Tables
Controller Prog. Features & Defaults ........9
Table 1 Hook-Up Diagram Selection ....................14
Table Parts List .................................................23
Getting Other Information and publications 3
MD4000 General Information
Shipping Damage....................................................4
General ...................................................................4
Theory of Operation ................................................4
 ControllerCertications ...........................................4
Specications/Features for MD4000 Series Controller
MD4000 Controller ..................................................5
Mounting the Controller
Installation Instructions............................................5
Temperature Sensors
Two Optional Sensor Inputs ....................................5
Temperature Sensor Logic
Using Multiple Sensors ...........................................5
Basic MD4000 Controller Input/Output Specs.
MD4000 Controller Connections .............................6
Located in the MD4000 panel Box
Unit #1 & Unit #2 Terminal Block .............................6
Specications/Features for Alarm Boards
MD4000-B & -BC w/Controller Alarms ....................7
Low Voltage Field Wiring
Circuitry in the MD4000...........................................7
Controller Grounding
Earth ground ...........................................................7
Controller power-Up
Time Delay on Power-Up ........................................7
Fire Suppression Circuit
Disabling the MD4000 .............................................8
Staging Delay periods
Stages 1 - 4 .............................................................8
Blower Operation
Various Blower Options ...........................................8
Advance (Swap) Lead/Lag Unit Feature
Manual Switching of Units .......................................8
Accelerate Timer Feature
Testing the Timer Function ......................................8
General programming Overview
Buttons & Function ..................................................9
Heating Sequence of Operation ............................10
Specications Opt. Remote Comm. Board
CB4000 Communications Board ......................11-12
Controller Wiring
Refer to Connection Diagram................................13
Security (Locking) Feature
Locking and Unlocking the MD4000 .....................13
Generator Run / Economizer Shutdown Feature
Standby Generator Disable Operation ..................13
Backup DC power Connection
Input Connections Available ..................................13