HLC-1000 High-limit Humidity Control

Transcription

1 FANs 216, Product/Technical Bulletin HLC-1000 Issue Date 1197 HLC-1000 High-limit Humidity Control The HLC-1000 is designed to limit duct humidity by comparing a controller s request for humidification with the humidity present in a duct. Like the H-3610, its pneumatic counterpart, the HLC-1000 will proportionately reduce its output signal to the humidification equipment as duct RH approaches a user-defined, high-limit setpoint. As a result, the HLC-1000 can help prevent excess condensation in a duct. ASHRAE Standard outlines that duct humidity greater than 70% can lead to the growth of fungal contaminants. The HLC-1000 can help compare and control duct humidity based on state, local, or ASHRAE guidelines. Figure 1: HLC-1000 High-limit Humidity Control Features and Benefits Adjustable High-limit Setpoint: 60-95% RH 5 to 30% RH Adjustable Proportional Band 0 to 10 VDC or 0 to 20 ma Input and Output Signals All-Polymer TM Humidity Sensor Temperature Sensor and High-limit Humidity Sensor in One Unit Easily Accessed Terminal Block SPST (Single-Pole, Single- Throw) Normally Open Relay Contacts Enables the user to define the maximum humidity level allowed in the duct; helps protect against saturation Prevents humidification equipment from cycling excessively; stabilizes system operation Interfaces with a wide variety of controllers and electronic actuators Provides accurate and reliable humidity sensing with improved resistance to chemical corrosion Eliminates the need for the purchase and installation of separate sensors; saves time and money Facilitates wiring, reducing installation time Accommodates On/Off humidification equipment; can be used for alarm indication 1997 Johnson Controls, Inc. 1 Part No , Rev. B Code No. LIT

2 Product Overview The HLC-1000 High-limit Humidity Control generates a 0 to 10 VDC or 0 to 20 ma signal based on duct RH to help regulate duct humidity by overriding a system controller s demand for humidification when duct humidity exceeds a user-defined, high-limit setpoint. When used as a standalone controller, the HLC-1000 delivers a proportional or On/Off relay output to a humidifier as duct RH approaches the preset high-limit setpoint. The HLC-1000 can be powered from either a separate 24 VAC transformer or directly from the controller. The humidity sensor s All-Polymer construction contains no metal, increasing the unit s life span in harsh environments. The temperature sensor, which is isolated from and operates independently of the high-limit function, is constructed of a thin-film nickel material that provides 1000 ohms of resistance at 70 F/21 C. The temperature sensor can be used whenever duct temperature measurement is needed for other HVAC operations. Application Overview The HLC-1000 has three main applications: High-limit Override Control (proportional or two position) that interfaces with a system controller. (See Figures 3 and 4.) Standalone Proportional Control (See Figure 6.) Standalone Two-position Control (See Figure 6.) High-limit Override Control Operation When used as a high-limit override control with a system controller, the HLC-1000 operates as follows: 1. The HLC-1000 accepts a 0 to 10 VDC or 0 to 20 ma input from a system controller VDC or 0-20 ma Input from the System HLC-1000's Internal Signal (Using All-polymer Element) (20) VDC (ma) 0 (0) 3. Output to the Humidification (Lower of the Two Signals) Setpoint: A djustable from 60-90% RH Proportional Band: Adjustable from 5-30% RH Figure 2: HLC-1000 Internal Calculation and Output Selection 2. The HLC-1000 calculates an internal 0 to 10 VDC (0 to 20 ma) signal as shown in Figure 2, which is a function of the following: the setpoint or maximum humidity allowed in the supply air duct, which is user adjustable from 60 to 95% RH the proportional band or the range of humidity below the setpoint over which the control signal is modified (user adjustable from 5 to 30%) 3. The HLC-1000 compares the two signals (from Steps 1 and 2), and outputs the lower of the two signals to the humidification equipment. Example: If the high-limit setpoint is 90%, the proportional band is 20%, duct RH is 80%, and the controller input is 7 VDC, then the HLC-1000 would output its own signal of 5 VDC to the humidification equipment since 5 VDC is lower than the system controller s signal. 2 HLC-1000 High-limit Humidity Control Product/Technical Bulletin

3 Sample Configurations The HLC-1000 will provide high-limit override control when linked with a system controller or linked with another HLC (See Figures 3 and 4.) Humidifer System HLC-1000 is mounted at least 8 feet downstream from the humidification equipment. Space or Return Air RH Sensor Figure 3: HLC-1000 as a High-limit Override Control with a System HLC-1000 Controlling Return Air or Space RH Standalone Proportional Humidity Control Operation When standalone proportional duct humidity control is desired, the HLC-1000 s input jumper is set to no input. When duct humidity approaches the user-defined (high-limit) setpoint, the HLC-1000 will proportionately reduce its output to the humidification equipment. (See Figure 5.) A sample configuration is shown in Figure 6. HLC-1000 Output 10 (20) VDC (ma) 2 (4) 0% RH in Duct Supply Air Setpoint Adjustable from 60-95% 100% Proportional Band: Adjustable from 50-30% RH Figure 5: HLC-1000 Operating as a Standalone Control Sample Configuration Humidifer Humidifer HLC-1000 (Mounted in Return Air or Space) HLC-1000 is mounted at least 8 feet downstream from the humidification equipment and provides high-limit control. Figure 4: HLC-1000 as a High-limit Override Control when Linked with Another HLC-1000 Compatible s When used as a high-limit override control, the HLC-1000 can be configured for the following controllers: AHU (Air Handling Unit) DCM (Digital Control Module) via an FM-OAE (Output Analog Electric Function Module) DX-9100 System 350 TM (with a W351) Generic applications Figure 6: HLC-1000 as a Standalone Proportional or Two Position Control Standalone Two Position Control Operation The HLC-1000 also provides a SPST relay output, which can be used with On/Off equipment. The relay contacts open at setpoint and close at setpoint minus proportional band. (See Figure 7.) 100 % RH 0 Setpoint Off On Proportional Band = Differential Figure 7: HLC-1000 Relay Operation HLC-1000 High-limit Humidity Control Product/Technical Bulletin 3

4 Temperature Sensor The HLC-1000 features an integral temperature sensor that is accurate to ±0.34 F/0.18 C at 70 F/21 C. The sensor provides 1k ohm of resistance at 70 F/21 C and operates independently of the high-limit humidity control function. (See Figure 8.) R esistance (Ohm s) Temperature, F/ C Figure 8: Resistance vs. Temperature Relationship for the Thin-film Nickel Sensor (Standard Johnson Controls Nickel Sensor Curve) D imensions 3-1/ /32 83 Diameter 3/ / / / / /16 14 Diameter 7/ / / / /32 25 Figure 9: HLC-1000 Dimensions, in./mm 2-15/16 74 Location Considerations When selecting a location for the HLC-1000, consider the following: Position: The HLC-1000 is designed for duct mounting in any position except with the probe tip pointed up. Duct Diameter: A minimum diameter (round ducts) or width (square ducts) of 12 in./305 mm is recommended. Air Stratification (when control is mounted on the discharge side of the fan): Mount the unit where duct air and water vapor from humidification equipment are sufficiently mixed. Avoid areas where the probe might be prone to condensation. As a general guideline, mount the HLC-1000 at least 8 feet downstream from most humidification equipment. Confirm that the HLC-1000 will be placed far enough away from the equipment where water vapor is dispersed. Minimum Air Velocity: 600 feet per minute (fpm) will typically maintain a time constant of one minute.! WARNING: The HLC-1000 is designed for use only with operating controls. Where an operating control failure would result in personal injury and/or loss of property, it is the responsibility of the installer to add devices (safety, limit controls) or systems (alarms, supervisory) that protect against, or warn of, control failure. Tools Needed hole saw with 1 in. blade drill with 1/8 in. drill bit screwdriver, flat-blade pliers gasket, sealer, or other means to seal the area between the unit and the duct 4 HLC-1000 High-limit Humidity Control Product/Technical Bulletin

5 M ounting Remove any excess insulation from the outside of the duct that would inhibit the probe from extending a minimum of 3 in./76.2 mm into the air stream, and proceed as follows: 1. Make a 1 in./25.4 mm diameter hole in the duct for inserting the probe. 2. Pull the square plastic cover off the aluminum housing, and insert the probe into the duct. 3. Using the housing as a template, mark the two screw holes. 4. Remove the HLC-1000, and drill two 1/8 in./3.175 mm holes. 5. To prevent duct air leakage, use a gasket, sealer, or other means to seal the area between the unit and the duct. 6. Secure the housing to the duct using the two No. 8 self-tapping screws provided. 7. Wire the unit according to the Wiring section. 8. Using pliers, break out the plastic knockout on the cover to accommodate the conduit. 9. Select the appropriate input and output jumpers for the application as detailed in the Commissioning section and in Figure 12. The HLC-1000 is factory set for a 0-10 VDC (both input and output) application. See Figure 12 for specific jumper positions. 10. Use the adjustment potentiometers to set the high-limit setpoint and the proportional band. Refer to the Commissioning section. 11. Press the plastic cover onto the aluminum base. W iring! WARNING: Shock Hazard. Disconnect the power supply before wiring connections are made to prevent electrical shock or possible damage to the equipment. IMPORTANT: Make all wiring connections in accordance with the National Electrical Code and local regulations. To wire the HLC-1000: 1. Route the wires from the controller to the HLC-1000 through the conduit hole in the aluminum housing. Use 16 to 24 AWG wire; 18 AWG is recommended. (Refer to Table 1 for wiring terminal details.) 2. Make wire connections to the screw terminals; refer to the wiring diagrams (Figures 10 and 11) as necessary.! CAUTION: Damage Hazard. Check all the connections before applying power to the system. Short-circuited or misconnected wires will permanently damage the unit. Table 1: Wiring Terminal Information Termina l Terminal Designatio n Polarity Source/ Destination Power + From the System or Separate 24 VAC Transformer COM Power, Input, and Output IN ma or 0-10 VDC from the System OUT + To the Humidification 5 TEMP N/A 1k ohm Nickel Temperature Sensor 6 TEMP N/A 7 Relay 8 Relay N/A For On/Off Humidity HLC-1000 High-limit Humidity Control Product/Technical Bulletin 5

6 Humidification Note: See Figure 12 for HLC-1000 jumper locations that are appropriate for the application. 24 VAC Transformer System Figure 10: Typical Application of an HLC-1000 Powered by a 24 VAC Transformer for Generic Applications HLC- HLC Note: See Figure 12 for the HLC-1000 output jumper setting that is appropriate for the humidification equipment used in the application. The HLC-1000's input should be set to "no input." Input Jumper: No Input Note: As a general rule, setting the proportional band to the larger numbers possible will prevent excessive cycling of the humidification equipment. This will ensure optimum system performance without oscillation. 3. Select the appropriate input and output jumpers for the application. If the HLC-1000 is used as a standalone humidity control (see Figure 11), the input jumper should be set to no input as detailed in Figure 12. Set the output jumper based on what type of signal the humidifier receives. If the HLC-1000 is used as a high-limit override control, refer to Table 2 for jumper positions. High-limit Setpoint Potentiometer Terminal Block (See Table 1 for terminal designations.) Mounting Screw Hole Proportional Band Potentiometer Humidification 24 VAC Transformer Figure 11: Typical Application of the HLC-1000 When Used as a Standalone C ommissioning Commission the HLC-1000 using the following steps: 1. With a small, flat-blade screwdriver, adjust the high-limit setpoint potentiometer to the RH level at which the humidification equipment should be completely off. (See Figure 12.) The setpoint potentiometer can be adjusted from 60 to 95% RH. 2. With a small, flat-blade screwdriver, adjust the proportional band potentiometer to the desired range of RH below the setpoint. (See Figure 12.) Setpoint minus proportional band is the highest duct humidity reading at which the HLC-1000 will allow the humidity equipment to be fully on. The proportional band potentiometer can be adjusted from 5 to 30%. No Input (Standalone Control Applications) Input Jumper 0-10 VDC (Factory Set) 0-20 ma Mounting Screw Hole Output Jumper 0-10 VDC or Relay (Factory Set) Figure 12: Inner View of the HLC ma 6 HLC-1000 High-limit Humidity Control Product/Technical Bulletin

7 Table 2: Jumper Positions When the HLC-1000 is Applied as a High-limit Override Input Jumper Position Output Jumper Position AHU 0-20 ma User Selectable: See Figure 12. LCP 0-10 VDC User Selectable: See Figure 12. DCM/FM-OAE 0-10 VDC User Selectable: See Figure 12. System 350/W351 No Input 0-10 VDC Generic T roubleshooting User Selectable Troubleshoot problems with the HLC-1000 using the following steps: 1. Check wiring. Make sure the power supply is functioning and wired properly to the HLC In addition, check the output wiring for improper connections. 2. Verify jumper positions. If the HLC-1000 is not delivering an output, check the jumper positions and make sure they are appropriately selected for the application. Refer to the proper wiring diagram in this bulletin or Figure 12 for jumper locations. 3. Check the proportional band setting. If the humidification equipment is cycling excessively, the proportional band setting may be too small. To correct the problem, try setting the proportional band to a larger value. See Figure 12 for potentiometer location. 4. Check the high-limit setpoint setting. If room RH never reaches the desired ambient RH level, the HLC-1000 s setpoint may have been set too low. Gradually raise the setpoint and monitor the results. Make sure, however, that the setpoint value will not be too high. A high setpoint could cause excess moisture to collect in the duct. 5. Verify the system controller is operating properly. Refer to the appropriate controller documentation. 6. Verify the HLC-1000 s output. If the HLC-1000 s output is still inaccurate after performing Steps 4 and 5, then: a. Measure duct RH with a humidity measuring device. Note: The HLC-1000 s RH sensor is extremely accurate; therefore, an instrument with greater accuracy must be used, e.g., an optical dew point hygrometer. b. Measure the output of the HLC using a DVM (Digital Volt Meter) or a milliampere meter. If using a DVM, connect the DVM to Terminals 4 (OUT) and 2 (COM) of the HLC c. Measure the system controller s output (input to the HLC-1000) using the DVM or the milliampere meter. d. Note the proportional band setting and find the HLC-1000 s output based on Steps 6b and 6c above. If duct RH is: below the proportional band, the output should be equal to the output from the system controller (input to the HLC-1000). above the proportional band, the output should be 0 VDC/mA. inside the proportional band, the HLC-1000 s output is calculated as follows: HLC-1000's internally generated signal = (X) * Setpoint - Measured RH Proportional Band Where: X = The full scale output (10 VDC or 20 ma) of HLC-1000 Ordering Information To order an HLC-1000 High-limit Humidity Control, contact your nearest Johnson Controls representative and specify the complete Product Code Number HLC Repair and Replacement Field repairs must not be made. For a replacement, contact the nearest Johnson Controls representative. HLC-1000 High-limit Humidity Control Product/Technical Bulletin 7

8 S pecifications Product HLC High-limit Humidity Control Power Requirements Acceptable Wire Gauges Element Time Constant Sensing Accuracy Humidity Element If proportional output is used: 20 to 30 VAC, 1.1 VA at 50/60 Hz or 12 to 30 VDC, 22 ma DC If relay output is used: 20 to 30 VAC, 1.1 VA at 50/60 Hz or 20 to 30 VDC, 22 ma DC 16 to 24 AWG (18 AWG is recommended.) Less than 120 seconds; between 50 to 90% at airflow of 0.8 ft/min. (0.24 m/min.) ±5% RH at 80% RH at 78 F/25 C All-Polymer, capacitive sensor Enclosure Material Enclosure: Anodized aluminum Cover and Probe Tip: LEXAN 950 Thermoplastic Adjustable RH Setpoint Adjustable Proportional Band Temperature Element Resistance Accuracy Temperature Coefficient Input Control Signal Input Impedance Output Control Signal Output Load Relay Contacts Relay Contact Rating Agency Listings Ambient Operating Conditions Ambient Storage Conditions 60 to 95% RH 5 to 30% RH Thin-film nickel 1k ohm at 70 F/21 C ±0.34 F/0.18 C at 70 F/21 C Approximately +3 ohms/ F; 5 ohms/ C 0 to 10 VDC or 0 to 20 ma Voltage: 20k ohms Current: 500 ohms 0 to 10 VDC or 0 to 20 ma Voltage 1k ohm Current 500 ohms SPST, Normally Open Open at setpoint Closed at setpoint minus proportional band Maximum: 4 Ampere, 24 VAC; Pilot Duty 42.4 VA at 24 VAC Minimum: 100 ma at 5 VDC UL Listing and CSA Certification 32 to 150 F/0 to 66 C; 0-100% RH non-condensing; 90 F/32 C maximum dew point -40 to 150 F/-40 to 66 C; 0 to 100% RH; 90 F/32 C maximum dew point Dimensions Overall (H x L x W): 3.3 in. x 3.3 in. x 7.9 in./83 mm x 83 mm x 2200 mm Probe (L x D): 6.0 in. x 0.9 in./152.4 mm x 24.9 mm Shipping Weight 0.7 lb/0.03 kg The performance specifications are nominal and conform to acceptable industry standards. For application at conditions beyond these specifications, consult the local Johnson Controls office. Johnson Controls, Inc. shall not be liable for damages resulting from misapplication or misuse of its product. Controls Group 507 E. Michigan Street P.O. Box 423 Milwaukee, WI Printed in U.S.A. 8 HLC-1000 High-limit Humidity Control Product/Technical Bulletin