Installation
18
Special Installation and Operating Instructions
Tankless Water Heaters with Optional D1 or DC Controller Options
Pin-Out Diagram for Electrical Wiring
The controller is shipped with the D1 option deactivated. Contact Laars to get the unlock code to activate the
ption.
DC Option Pin-Out
D1 Option Pin-Out
Pin
Name
Description
Pin
Name
Description
T+/R+
2
RS-485 Transmit/Receive
Non-Inverting Input/Output
Negative
3
Return Current Path for
+Current, Pin 4
3
Signal
Ground
+Current
4
Signal Ground
Supply 4-20mA Current to
Set Heater Temperature
T-/R-
4
RS-485 Transmit/Receive
Inverting Input/Output
Negative
7
Return Current Path for
+Current, Pin 8
1, 5,
6-9
+Current
8
No Connection
--
Supply 40-20mA Current to
Monitor Heater
Temperature
1, 2, 5,
6, 9
No Connection
