Distech Controls ECL-PTU Series - Page 8

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Figure12: Powered Relay outputs
Wiring Relay Contact Outputs
The ECL-PTU-107, ECL-PTU-207, ECL-PTU-208 and ECL-PTU-308 have one (1) relay contact output (DO4-C4) which can switch up to 9 A (resistive)
for electric heater control up to 255 VAC. For example, this output can handle electric heaters up to 2 kW @ 230 VAC.
The ECL-PTU-307 has two (2) relay contact outputs (DO4-C4 and DO11-C11) which can switch up to 6 A (resistive) for electric heater control up to 255
VAC. For example, this output can handle electric heaters up to 1.4 kW @ 230 VAC.
If more power is needed, a relay must be connected to the relay contact output.
£ All relay contact output connectors accept wires between 1.5 mm² (16 AWG) and 2.5 mm² (14 AWG). Select proper gauge according
to the current load.
£ All digital relay contact outputs are normally open.
£ Heater relay outputs are unpowered. You must use the same Live conductor (power source) to power the heater as the one used to
power the controller.
£ It is recommended to use an appropriate external protection if connected to a highly inductive load.
£ It is recommended to use a 10 A fast-acting, high-breaking fuse to protect the heater relay contact output against short circuit/over-
load conditions.
Figure13: Relay Contact outputs - Electric Heater (I-Electric Heater < I-Max )
Figure14: Relay Contact outputs - Electric Heater (I-Electric Heater > I-Max )
Wiring Triac Outputs
Depending on models, triac outputs provide either the same voltage as the power supply (100-240 VAC) or 24 VAC. Refer to the controller’s Datasheet
for further specifications.
The triac outputs can also be used to turn equipment and devices on and off (two-state outputs) and to control valve and damper actuators using Pulse
Width Modulation (PWM).
Controller Digital (Triac) Outputs
(100-240 VAC)
Digital (Triac) Outputs
(24VAC)
ECL-PTU-107 DO5 - DO6 -
ECL-PTU-207 DO5 - DO6 -
ECL-PTU-208 - DO5 - DO6
ECL-PTU-307 DO5 - DO6 – DO9 – DO10 -