13
2-10 VDC or 4-20 mA External Input
Signal
The external input signal can be selected to be either
0-10 VDC or 2-10 VDC. When the 2-10 VDC range is
selected, an input of 2 VDC corresponds to a heater
target temperature of 50ºF (10ºC). An input voltage of
10 VDC corresponds to a heater target temperature of
210º F (99º C). As the voltage varies between 2 VDC
and 10 VDC, the heater target temperature varies lin-
early between 50ºF (10ºC) and 210º F (99º C). If a
voltage below 1.5 VDC is received the heater target
temperature is displayed as “ - - - “ indicating that there
is no longer an internal CFH.
A 4-20 mA signal can be converted to a 2-10 VDC sig-
nal by installing a 500 ohm resistor in parallel to the
input signal on the controller’s terminals (terminals 9 &
10).
OFFSET
The offset setting allow the heater target temperature
to be fine tuned to the external input signal. The con-
troller reads the external input signal and converts
this to a heater target temperature. The offset is then
added to the heater target temperature.
Example
Range = 0-10 VDC
Input = 7 VDC 157º F (69º C)
Offset = + 5º F (3º C) + 5º F (3º C)
Heater Target =
162º F (72º C)
External Direct Drive Operation
(Mode 8)
When Mode 8 is selected, the controller allows for an
external control to operate the heater through an
analog direct drive input signal provided by a heater
sequencing control, such as the
Raypak Temp-
Tracker Mod+ Hybrid
. When in mode 8, the indirect
DHW override is disabled.
Direct Drive Input Signal
An external heater sequencer provides a positive 0-
10 VDC input signal to the contV input
(terminal 10). The negative VDC signal is applied to
the Com/- input (terminal 9).
The heater remains off while the direct drive input
signal is between 0.0 to 0.5 VDC. The Stage 1 con-
tact remains on as long as the direct drive input
signal reaches or exceeds 0.5 VDC. The Stage 2
contact is activated once the direct drive input signal
reaches or exceeds 3.0 VDC. The Stage 3 contact is
activated once the direct drive input signal reaches or
exceeds 5.5 VDC. The Stage 4 contact is activated
once the direct drive input signal reaches or exceeds
8.0 VDC.
PUMP OPERATION
The pump is turned on as soon as the direct drive input
signal reaches 0.5 VDC. Once the direct drive input
signal falls below 0.5 VDC, the pump continues to
operate until the Pump DLY purge expires, then the
pump shuts off.
2-10 VDC
4-20 mA*
Heater Target
0
0
- - - (OFF)
1
2
- - - (OFF)
2
4
50ºF (10ºC)
3
6
70ºF (21ºC)
4
8
90ºF (32ºC)
5
10
110ºF (43ºC)
6
12
130ºF (54ºC)
7
14
150ºF (66ºC)
8
16
170ºF (77ºC)
9
18
190ºF (88ºC)
10
20
210ºF (99ºC)
*Requires a 500 Ω resistor
Table C: 2-10 VDC or 4-20mA External Input (Mode 7)
0-10 VDC
0-20 mA*
Heater Target
0
0
- - - (OFF)
1
2
50ºF (10ºC)
2
4
68ºF (20ºC)
3
6
86ºF (30ºC)
4
8
103ºF (39ºC)
5
10
121ºF (49ºC)
6
12
139ºF (59ºC)
7
14
157ºF (69ºC)
8
16
174ºF (79ºC)
9
18
192ºF (89ºC)
10
20
210ºF (99ºC)
*Requires a 500 Ω resistor
Table B: 0-10 VDC or 0-20mA External Input (Mode 7)
