Fig 2. Powering an HS-EMS400 Thermostat with a Stand-alone Transformer
Fig 1. Wiring Diagram for One Heating/Cooling System with One HS-EMS400 Thermostat
Warning! Do not remove the internal jumper (shunt). Connect to O or B terminal as
specified by equipment. Do not connect to both O and B terminals.
Thermistor Temperature Sensor
HS-EMS400
W1
Y1
G
R
24V
24V(c)
CLK1
CLK2
RS2
RS1
RS+V
X1
X2
R/24V shunt. Remove if
thermostat power is not
supplied by equipment.
Free Light / LED1
Free Light / LED2
O
LED2
LED1
DIP SW7
DIP SW8
Display
B
Emergency Heat LED
(Center)
Escort5580TC/
VPM5580TC
X
1
X
2
RS
+V
X
2
X
1
RS
+V
RS1
RS2
CLK1
CLK2
24V(c)
24V
R
G
W1
Y1
24V(c)
24V
G
W1
Y1
Auxiliary Heat
Compressor
Fan
Power - Hot
Power - Common
Heat Pump
System
HS-EMS400
(Backplate)
LED1
LED2
O
O
Reversing Valve - Cool Mode
B
Reversing Valve - Heat Mode
B
Output Terminal Functions
LED1 .................Free light for status or function indication.
LED2 .................Free light for status or function indication.
CLK1 .................Use with dry contact relay for alternate set points.
CLK2 .................Use with dry contact relay for alternate set points.
RS2 ....................To Outdoor/Indoor remote sensors.
RS1 ....................To Outdoor/Indoor remote sensors.
RS+V .................To Outdoor/Indoor remote sensors and
to Escort5580TC/VPM5580TC.
X2 ......................To Escort5580TC/VPM5580TC.
X1 ......................To Escort5580TC/VPM5580TC.
W1..................... Auxiliary heat is energized as back-up or emergency heat.
Y1...................... Compressor is energized with a call for heating or cooling.
G........................ Fan is energized with a call for heating or cooling or by press-
ing the fan button.
R........................ Independent switching voltage.
24V.................... 24 V
AC
Hot from equipment transformer.
24V(
C
)............... 24 V
AC
Common from equipment transformer.
O........................ Energizes the reversing valve continuously in cool mode.
B........................ Energizes the reversing valve continuously in heat or off mode.
Warning!: Remove the internal jumper (shunt) before connecting the stand-alone transformer. Connect to O
or B terminal as specified by equipment. Do NOT connect to both O and B terminals.
Escort5580TC/
VPM5580TC
X
1
X
2
RS
+V
X
2
X
1
RS
+V
RS1
RS2
CLK1
CLK2
24V(c)
24V
R
G
W1
Y1
24V(c)
24V
G
W1
Y1
Auxiliary Heat
Compressor
Fan
Heat Pump
System
HS-EMS400
(Backplate)
LED1
LED2
O
O
Line Voltage
Common
Hot
24V
AC
Transformer
B
B
Reversing Valve - Cool Mode
Reversing Valve - Heat Mode
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