D4-HTCT

This device incorporates a digital temperature controller and a 24 hour timer with two “on” times and two “off” times. The two functions operate independently and control separate relays.
The temperature controller interfaces directly with 3-wire PT100 temperature probe. (0.1 °C resolution).
The relay may be configured for heating, cooling, heating alarm or cooling alarm functionality.
The parameter settings may be locked and code protected to avoid changes from being made by unauthorized personnel.
The menu may be reduced to allow changes to only the most commonly adjusted parameters. This reduces the risk that one of the mode advanced parameters are accedentally changed.
The adjustable range of the temperature set points may be limited to avoid temperatures from being enetered that may cause damage to the overall system.

Operation:
The temperature relay changes state when the probe temperature reaches the pre-set temperature. Once the temperature has changed (in the opposite direction) by the pre-set hysteresis amount, the relay resumes its original state.
The timer relay is energised whenever the current time falls between “ON 1” time and “OFF 1” time, or “ON 2” time and “OFF 2” time.
Note: This device does not keep track of time during power failures. The current time is memorized once per hour. This results in a loss of time of up to one hour PLUS the duration of the power failure.

Relay Operation modes:

Heating mode:
The relay is energised while the temperature rises to the set point value. When the set-point is reached, the relay de-energizes until the temperature drops below the set-point by the hysteresis amount of degrees.

Heating alarm mode:
Similar to heating mode except that the relay is de-energised until the set point is reached. Once energised, the temperature must drop below the set-point by the hysteresis amount before it will de-energise. The latch facility may be used to keep the relay energised until the latch is removed (even if the temperature has dropped sufficiently)

Cooling mode:
The relay is energised while the temperature drops to the set point value. When the set-point is reached, the relay de-energizes until the temperature rises above the set-point by the hysteresis amount of degrees.

Cooling alarm mode:
Similar to cooling mode except that the relay is de-energised until the set point is reached. Once energised, the temperature must rise above the set-point by the hysteresis amount before it will de-energise. The latch facility may be used to keep the relay energised until the latch is removed (even if the temperature has increased sufficiently)

Specifications:

Temperature range:         -50.0 °C to + 440.0 °C

Resolution:                      0.1°C

Accuracy:                          ±0.5 °C (@ 25 °C ambient )

Input voltage:                  ±15% of rated input

Probe:                               PT100 (38.5 ohm/ 100 °C)

Time:                                ±0.05% 

User Manual