Polygyr -Compact Immersion Temperature Controller

Transcription

1 Document No. CM1N3409E-P25 Polygyr -Compact Immersion Temperature Controller Features Two outputs for heating Continuous control signal PI control Electronic 24 Vac Application The RCE61.21 is used in installations for domestic water heating where two actuators must be controlled in sequence. The temperature controlled by the RCE61.21 can be shifted by: the outdoor temperature, e.g., for weather dependent control a building automation system to obtain set point adjustment (fixed value shift). T T SASC0029R1 RCE61.21 Immersion Temperature Controller Valve with Actuator Valve with Actuator Figure 1. Application Example. Product Number Ordering RCE61.21 When ordering, specify quantity, product number and description.

2 Polygyr-Compact Immersion Temperature Controller Function The RCE61.21 provides PI control. Its proportional band is adjustable and three different integral action times can be selected. The controller compares the actual value with the set point and generates two control signals when a deviation occurs. The control signals are switched in sequence. They are continuous and have a range of 0-10 Vdc. When the control signal changes from 0 10 Vdc, the correcting variable changes from 0-100%, i.e., there is a proportional relationship between the correcting variable and the control signal. Y 10V SASC0030R1 Q Xp2 Xp1 0 Q Load Signal voltage Signal voltage Heating Figure 2. Design Features The RCE61.21 is a small, electronic controller that combines electronics, setting unit and sensing element into one unit. The casing is plastic with a removable cover. The immersion detector stem with nickel measuring element is fitted at the rear of the unit. All setting devices and connecting terminals are contained in the housing and accessible only when the cover is removed. 1 Setting scale 2 Slider for setting the desired value 3 Setting potentiometer for P band Xp1 4 Setting potentiometer for P band Xp2 5 Connecting terminals 6 Central mounting screw 7 Service plug 8 Shorting plug for integral action time Figure 3. The scale and slider for setting the desired temperature can be seen through a window in the cover. Knock-out holes (Pg11) provide entry for the cables. To facilitate mounting in the pipe work, the controller has a male thread and mounting nut (standard version). The immersion detector stem, threaded bushing and mounting nut are made of corrosion-proof CrNiMo steel. The latter provides metallic insulation, so a protection well is not required (see Accessories). The controller should not be removed form the pipe work if servicing is required. Two printed circuit boards carry the controller electronics and setting devices. They can be removed from the housing after the cables have been disconnected and the central mounting screw loosened. Page 2

3 Polygyr-Compact Immersion Temperature Controller Technical Instructions Accessories If required, a protection well can be ordered: Protection well P0, nickel plated brass Protection well P6, St 18/8/2,5 CrNiMo Unit Combinations The RCE61.21 can control various units with the following characteristics: Remote Setting Units Type of control 0 10 Vdc Operating voltage 24 Vac The FZA21.11 remote setting unit is used for remote setting of the desired value. Specifications Operating voltage 24 Vac ± 20% Frequency Hz Power consumption 1 VA Control signal: Voltage 0 10 Vdc, continuous Current 1 ma Integral action times (selectable) PI 1 10 seconds PI 2 60 seconds PI 3 NI F (0 C) Measuring element LG-Ni F (0 C) Time constant Standard version 4 seconds With protection well 25 seconds Setting ranges Set point F ( C) Proportional band Xp1 5 50%, 9-90 F Proportional band Xp2 5 50%, 9 90 F Permissible nominal pressure P6 Permissible detector temperature 266 F (130 C) Permissible ambient temperature: Operation F ( C) Transport and storage F ( C) Cable entry fitting Pg11 Connecting terminals for 2 x 14 AWG or 1 x 12 AWG Weight 0.55 lb. Application When the unit is switched off or the power supply interrupted (Terminal G), the regulating unit is automatically run to the closed or no-load position. A transformer is required to generate the operating voltage of 24 Vac. When several units are connected, the size of the transformer is determined by adding up the power consumption of the individual units. See Wiring Diagrams for connecting terminal designations. Actuators For fast controlled systems, always use an SKD62 or SQX61 actuator. Page 3

4 Polygyr-Compact Immersion Temperature Controller Compensation If a compensation input is used, attention must be paid to its input signal: Terminal Z1: Terminal Z3: Input for universal compensation. The signal + 5V ± 10V corresponds to ± 100% of the theoretical setting range. Input for set point adjustment (fixed value shift). The signal + 5V ± 5V corresponds to ± 10% of the theoretical setting range. Mounting Mounting location: With heat exchanger control, mount as closely as possible to the heat exchanger, allowing for the permissible ambient temperature. A threaded fitting is required to mount the controller in the pipe work. Where possible, the fitting should be welded in a pipe bend so that the immersion detector stem faces the flow of water. The controller must be mounted at the side of the pipe if the warm air rising from the pipe work could cause the temperature of the unit to exceed 122 F (50 C). Installation Instructions are supplied with the unit. Commissioning To check the operation, P control can be provided by using the service plug. The correct operation of the regulating unit can be checked by setting the slider to its limit positions. With domestic hot water temperature control (mixing), the selected integral action time must be 10 s (plug position PI 1). If the factory settings must be changed, the following must be noted: In case of instability (controlled system oscillates): Xp must be increased. In case of instability although Xp is set to maximum value: integral action time must be increased. In case of excess stability (controlled system too slow): Xp must be decreased. The ration of the proportional bands Xp1 to Xp2 should roughly correspond to the ratio of the correcting spans of valves and. If auxiliary control functions (e.g., limitation, compensation) are fed to the main controller, the controlled value must first be adjusted, with no influence from the auxiliary control functions. The auxiliary values are adjusted only after the controlled value is adjusted. If a remote setting unit is used, the slider for setting the desired temperature must be set to ext. Page 4

5 Polygyr-Compact Immersion Temperature Controller Technical Instructions Wiring Diagrams The following wiring diagram only shows the fundamental layout. It does not contain the switch off functions and other switching functions which can vary from one installation to another according to the operating conditions. SP R M R1 RM Z1 Z3 G 24V~ SASC0018R1 SN G Y R M U G Y R M U R1 RCE61.21 Immersion Temperature Controller FZA21.11 Remote Setting Unit Actuator Actuator Figure 4. Basic Connections. Terminal Layout SASC0017R1 G R M Z1 Z3 Figure 5. Terminal Layout. G, Operating voltage 24 Vac G System potential (SP) System neutral (SN) M Measuring neutral R Set point signal Control signal 0 10 Vdc Control signal 0 10 Vdc Z1 Reference signal + 5V ± 10V Z3 Reference signal + 5V ± 5V Dimensions R 1/2" 4.02 SASC0031R1 ca Pg With Well 0.35 Figure 6. Dimensions in Inches. Information in this publication is based on current specifications. The company reserves the right to make changes in specifications and models as design improvements are introduced. Polygyr is a trademark of 2000 Landis & Staefa Division 1000 Deerfield Parkway Buffalo Grove, IL U.S.A. Document No. CM1N3409E-P25 Printed in the U.S.A. Page 5