3D Connexion mD4000-b Manuel D’Utilisation

Page de 23
Manual 2100-574
Page 
8 of 23
FIre suPPressIOn cIrcuIt 
To disable the MD4000 and shut down both air 
conditioners, terminals F1 and F2 may be used.  The F1 
and F2 terminals must be jumpered together for normal 
operation.  A normally closed (nc) set of dry contacts 
may be connected across the terminals and the factory 
jumper removed for use with a field-installed fire 
suppression system.  The contacts must open if a fire is 
detected.  See appropriate connection diagram - Figures 
1, 2 or 3 for this connection.  Contacts should be rated 
for pilot duty operation at 2 amp 24VAC minimum.  
Shielded wire (22-gauge minimum) must be used, and 
the shield must be grounded to the controller enclosure.
staGInG DelaY PerIODs
The following delays are built in for both cooling & heating: 
  Stage 1 – 
0 seconds for blower (if not already on as  
 
 continuous)
 
10 seconds for cooling or heating output
  Stage 2 – 
10 seconds after Stage 1 for blower
 
10 additional seconds for cooling or heating   
 output 
  Stage 3 – 
 10 seconds after Stage 2
  Stage 4 – 
 10 seconds after Stage 3
Note: For cooling Stages 1 and 2, the stage LED will    
blink for 10 seconds while the cooling output is delayed 
after that stage is called for.  There is also a delay after     
the stage is satisfied, and after the LED stops blinking,     
the  stage will turn off.  There is a minimum 10-second 
delay between stages 2 & 3, and 3 & 4, but no delayed 
output when stage is turned on or off, and LED for 
those stages will not blink.
blOWer OPeratIOn
The controller can be configured to have main HVAC 
blowers  cycle on and off on demand; have all blowers 
run continuously; or have the lead unit blower run 
continuously with the lag unit blower cycling on 
demand.  Default setting is the blower on the lead unit 
operates continuously.  There is also an option to have 
all blowers cycle on if one remote sensor is connected, 
and a temperature difference of more than 5F between 
any two sensors is observed.  This helps to redistribute 
the heat load within the structure and should reduce 
compressor operating time.
When any of the stages are satisfied, the stage  LED 
will blink for ten (10) seconds before the stage is 
actually turned off.
aDvance (sWaP) leaD/laG unIt 
Feature
Pressing the Advance button for one (1) second will 
cause the lead and lag units to change positions.  
This may be useful during service and maintenance 
procedures.  This function can also be done remotely by 
closing a contact across the Advance terminals on the 
main board.
accelerate tImer Feature
Pressing the UP arrow button for five (5) seconds 
will activate an accelerate (speed-up) mode, causing 
the normal changeover time increments of days to 
be reduced to seconds.  Example: 7 days becomes 
7 seconds.  When “ACC” displays, release button.  
Whichever LED is on, indicating lead unit will blink 
over for each second until the controller switches.  This 
is a check for the timer functionality.