Watts tekmar 294 User Manual

IOM-T-294 2205 © 2022 tekmar
39
The control accepts an analog signal to create a Remote
Setpoint Call when a 0-10 V(dc), 2-10 V(dc), or 4-20 mA signal
is applied to the EMS (+) and EMS (-) wiring terminals. The
control converts the analog signal into the appropriate boiler
target temperature. The most common source of this analog
signal is an Energy Management System (EMS). The Remote
Setpoint Call is displayed in the System Inputs screen.
The remote setpoint call uses the same wiring terminals as the
outdoor air sensor; therefore, the central heating call must be
off when this feature is on.
0-10 V(dc) or 0-20 mA
When Input EMS signal is set to 0-10 V (dc), the control uses
the following conversion table.
CONVERSION TABLE 0 - 10
0 - 20 MA* 0 - 10 V (DC) BOILER TARGET
0 0 – – – (OFF)
2 1 50°F (10.0°C)
4 2 68°F (20.0°C)
6 3 86°F (30.0°C)
8 4 103°F (39.5°C)
10 5 121°F (49.5°C)
12 6 139°F (59.5°C)
14 7 157°F (69.5°C)
16 8 174°F (79.0°C)
18 9 192°F (89.0°C)
20 10 210°F (99.0°C)
*Requires 500 Ω Resistor in Parallel
If a voltage below 0.5 V (dc) is received the boiler target tem-
perature is displayed as “– – –” indicating that there is no lon-
ger a call for heating.
A 0-20 mA signal can be converted to a 0-10 V (dc) signal by
installing a 500 Ω resistor between the EMS (+) and EMS (-)
terminals.
2-10 V(dc) or 4-20 mA
When Input EMS Signal is set to 2 - 10 V (dc), the control uses
the following conversion table.
*Requires 500 Ω Resistor in Parallel
CONVERSION TABLE 2 - 10
4 - 20 MA* 2 - 10 V (DC) BOILER TARGET
0 0 – – – (OFF)
4 2 50°F (10.0°C)
6 3 70°F (21.0°C)
8 4 90°F (32.0°C)
10 5 110°F (43.5°C)
12 6 130°F (54.5°C)
14 7 150°F (65.5°C)
16 8 170°F (76.5°C)
18 9 190°F (88.0°C)
20 10 210°F (99.0°C)
If a voltage below 1.5 V (dc) is received the boiler target tem-
perature is displayed as “– – –” indicating that there is no lon-
ger a call for heating.
A 4-20 mA signal can be converted to a 2-10 V (dc) signal by
installing a 500 Ω resistor between the EMS (+) and EMS (-)
terminals.
EMS Offset
The analog voltage signal may drop over the length of a long
wire. The Remote Setpoint includes an Input EMS Offset set-
ting to compensate if the boiler target does not match the
transmitting device.
Example
Range = 0 - 10 V (dc)
Input = 7 V (dc) 157°F (69°C)
Offset = +5°F (3°C) +5°F (3°C)
Boiler Target = 162°F (72°C)
Remote Setpoint Call
The control can communicate with tekmarNet
®
devices such
as thermostats, snow melting controls and setpoint controls to
maximize system efficiency and comfort. The devices call for
heat on the boiler system water temperature.
Indoor Temperature Feedback
tekmarNet Thermostats use Indoor Temperature Feedback
when connected to the 294 tekmarNet boiler bus. Indoor
Temperature Feedback automatically identifies the highest heat
loss thermostat and sets the central heating target so that this
thermostat operates at 100% on time. The remaining zones
have lower heat loss and operate at a lower duty cycle.
Device Count
The control counts all the tekmarNet devices and displays this
in the Settings > Heating Calls > tekmarNet menu.
Scenes
The 294 responds to the following tekmarNet
®
scenes:
SCENE RESPONSE
1 Occupied or Schedule
2 Away, operates Room at 62°F (16.5°C) and there is no DHW heating
3 Permanent Unoccupied
4 Occupied or Schedule
5 Occupied or Schedule
6 Temporary 3 hour Occupied
7 Temporary 3 hour Occupied
8 Temporary 3 hour Occupied
tekmarNet
®
4 Call

Watts tekmar 294 Specifications

General

Category	Controller
Number of Zones	4
Enclosure Rating	NEMA 1
Model	294
Input Voltage	24 VAC
Output Voltage	24 VAC
Operating Temperature	0 to 50°C