3D Connexion mD4000-b 사용자 설명서

Manual 2100-574

Page 

10 of 23

MD4000

decides Lead

unit

Spyder 1 is lead

Signals Spyder2

as lag.

Spyder 2 is lead

Signals Spyder1

as Lag

DC Amp load is read and

converted to building load

with the equation DCA *

106.4-.2455 = BTUH

Calculate

Available Cooling

(AC) for 1 econ

Available cooling =( SP-

MTD-OAT)*1.08*Airflow

If AC > BL

Calculate MAT

Start Econ 1

Stop Econ 2

Stop Blower 2

Yes

No

Calculate

Available cooling

for 2 econ

If AC*2 > BL

Yes

No

Start Lead

Compressor

Start Lead Blower

No

Is OAT suitable

for Cooling

Yes

If OAT <= SP-MTD

and Enthalpy is below

curve(if equipped

Determine Building

Load

Calculate MAT

Start Econ 1

Start Econ 2

Start Blower 2

Calculate MAT

Start Econ 1

Start Econ 2

Start Blower 2

Is RT

above SP

Yes

No

Stop Lead

Compressor

Is RT

above or

below SP

No

Yes

Calculate adjusted

building Load

(BL)

MAT will be adjusted to take

into account deviation from

setpoint

BL+((RT-SP)*Airflow*1.2)

Is RT

Below SP

No

Yes

Is RT

Above ALarn

Setpoint

Yes

Start Lag

Compressor

No

Allow econ

operation with

Compressor

No

Yes

Stop Econ 1

Stop Econ 2

Stop Blower 2

Is 2

nd

comp

Allowed

Yes

NO

MD4000-BCESDC/MD4000-BESDC

W/ AC UNITS W/ DC CONTROL

ECONOMIZERS

OAT = Outdoor Air Temperature

BL = Building Load

MDT = Minimum Temperature Differential

RT = Room Temperature

SP = Setpoint

AC = Available Cooling

1

st

 stage heating set point is the dead-band (db) below 

the 1

st

 stage cooling set point (the SP entered into the 

program).  The dead-band is adjustable from 2-40F, and 
factory default is 27F.

2

nd

 stage heating set point will operate at same inter 

stage differential as set for cooling mode.