18
HL-Series Tankless Heater
Installation
3/29/2018
Bradley •
215-1823 Rev. F; ECN 18-17-017
Special Instructions and Operating Instructions
Tankless Water Heaters with Optional D1 or DC Controller Options
Pin-Out Diagram for Electrical Wiring
2
3
4
3
4
7
8
DC Option Pin-Out
D1 Option Pin Out
T+/R+
Signal Ground
T-/R-
Negativ
e
+Current
Negativ
e
+Current
The controller is shipped with the D1 option deactivated. Contact the factory to get the unlock code
to activate the option.
DC Option Pin-Out
Pin
Name
Description
2
T+/R+
RS-485 Transmit/Receive
Non-Inverting Input/Output
3
Signal Ground Signal Ground
4
T-/R-
RS-485 Transmit/Receive
Inverting Input/Output
1, 5,
6-9
--
No Connection
D1 Option Pin-Out
Pin
Name
Description
3
Negative
Return Current Path for
+Current, Pin 4
4
+Current
Supply 4-20mA Current to
Set Heater Temperature
7
Negative
Return Current Path for
+Current, Pin 8
8
+Current
Supply 4-20mA Current to
Monitor Heater Temperature
1, 2, 5,
6, 9
No Connection
