- Data Brochure D 667 Snow Detector & Melting Control 667 03/09 The Snow Detector & Melting Control 667 is a microprocessor-based control which operates a snow melting system. The control can operate automatically when a Snow / Ice Sensor 090 is installed or the user can manually enable and / or disable the system. The 667 controls a variable speed injection pump to provide both boiler and slab protection.
How To Use The Data Brochure This brochure is organized into four main sections. They are: 1) Sequence of Operation, 2) Installation, 3) Control Settings, and 4) Troubleshooting. The Sequence of Operation section has 7 sub-sections. We recommend reading Section A: General of the Sequence of Operation, as this contains important information on the overall operation of the control. Then read to the sub-sections that apply to your installation.
Display Number Field Displays the current value of the selected item Item Field Displays an abbreviated name of the selected item Melt Demand Idle Demand WWSD Minimum Maximum Water Melting Menu Field Displays the current menu Status Field Displays the current status of the control's inputs, outputs and operation Buttons Selects Menus, Items and adjust settings Symbol Description Mixing Device Output Scale Shows output of injection pump. Arrows show whether the output is increasing or decreasing.
Sequence of Operation Section A Section B Section F Section G General Operation Page 4 - 5 Idling Operation Page 12 Snow Melting Page 5 - 7 Section C Boiler Operation Page 7 - 8 Section D Melting Enable / Disable Page 9 - 11 Section E Melting Operation Page 11 - 12 Delta ΔT Hours Page 13 Section A: General Operation POWERING UP THE CONTROL When the Snow Detector & Melting Control 667 is powered up, the control displays all LCD segments for 2 seconds, then the control type number in the LCD for
Section B: Snow Melting Section B1 General Snow Melting Section B1: General Snow Melting SLAB PROTECTION (ΔT MAX) The control can limit the rate at which heat is applied to the zone through the ΔT Max setting. The ΔT (delta T) is the temperature difference between the snow melting supply temperature and the snow melting return temperature. By limiting this temperature difference, the rate at which heat is applied to the zone can be controlled and thermal stresses in the slab can be minimized.
COLD WEATHER CUT OUT (CWCO) Maintaining the system at either the melting or idling temperature during extremely cold temperatures can be expensive or impossible. The control turns the snow melting system off when the outdoor air temperature drops below the Cold Weather Cut Out (CWCO) temperature. While the control is in CWCO, the word CWCO is displayed in the Status item in the VIEW menu. The heater in the sensor is kept on during CWCO until the control detects moisture.
Section C: Boiler Operation Section C1 Boiler Supply Sensor Section C2 Boiler Return Sensor Section C3 No Boiler Sensor Section C1: Boiler Supply Sensor BOILER SENSOR ON THE SUPPLY (Boil SENS = SUP) When operating a boiler that is dedicated to a snow melting system, the 667 is designed to operate the boiler as efficiently as possible. The boiler is cycled based on the mixing supply fluid temperature. This is to provide longer and more efficient boiler cycles.
If the AUTO differential is selected, the 667 automatically adjusts the Differential setting under the current load conditions to avoid short cycling. Off Differential On Time Section C2: Boiler Return Sensor BOILER SENSOR ON THE RETURN (Boil SENS = RET) The boiler sensor should be located on the boiler return if the 667 is one of many controls that can call for boiler operation. When in the return mode, the 667 provides a boiler enable through the Boiler contact.
Section D: Melting Enable / Disable Section D1 Snow Melting Enable Section D2 Snow Melting Disable Section D1: Snow Melting Enable The snow melting system can be enabled manually or automatically. A melting enable signal applied to the control places the system into the Melting mode. If a melting enable signal is applied once the system is already in the Melting mode, the control responds to the last command received.
15 16 Melt / Idle Demand External Melt Demand (DIP switch set to Melt Demand) The snow melting system is enabled when a voltage between 24 and 240 V (ac) is applied across the Melt / Idle Demand terminals (15 and 16). An external melt demand must be present for at least 4 seconds in order to start the snow melting system. If the RUN TIME reaches 0:00 and the external melt demand is still present, the control continues melting until the external melt demand is removed or the system is otherwise stopped.
External Idle Demand (DIP switch set to Idle Demand) The snow melting system is disabled when a voltage between 24 and 240 V (ac) is applied across the Melt / Idle Demand terminals (15 and 16). An external idle demand must be present for at least 4 seconds in order to stop the snow melting system. Note: This operation only occurs if the Idle Demand / Melt Demand DIP switch is set to the Idle Demand position.
Snow / Ice Sensor 090 The slab temperature is displayed as SLAB in the VIEW menu. This temperature is calculated from the edge and center sensors built into the 090. SLAB TARGET TEMPERATURE (SLB TRG) The SLAB TRG temperature is determined from the Melting setting, Idle setting and the outdoor air temperature. The control displays the temperature that it is currently trying to maintain at the slab sensor.
Section G: Δ T Hours (Relative Energy Usage) Section G1 ΔT Hours Section G1: Δ T Hours The control records the temperature difference (Δ T) multiplied by the number of hours the control is in the Melt or Idle modes. This allows the user to estimate the amount of energy used by the snow melt system. The energy consumption can be estimated by multiplying the Δ T Hours by the system flow rate (in US GPM) and by the constant K shown below.
Installation CAUTION Improper installation and operation of this control could result in damage to the equipment and possibly even personal injury. It is your responsibility to ensure that this control is safely installed to all applicable codes and standards. This electronic control is not intended for use as a primary limit control. Other controls that are intended and certified as safety limits must be placed into the control circuit. Do not open the control. Refer to qualified personnel for servicing.
16 Melt / Idle Demand Melt / Idle Demand To generate a melt demand or idle demand, a voltage between 24 V (ac) and 240 V (ac) must be applied across the Melt / Idle Demand terminals (15 and 16). 24 to 230 V (ac) L N Output Connections 19 20 Boiler Contacts Boiler The Boiler terminals (19 and 20) are an isolated output in the 667. There is no power available on these terminals from the control. These terminals are used as a switch to either make or break the boiler circuit.
13 14 Sensor and Unpowered Input Connections Do not apply power to these terminals as this will damage the control. Com Out Outdoor Sensor Connect the two wires from the Outdoor Sensor 070 to the Com and Out terminals (13 and 14). The outdoor sensor is used by the 667 to measure the outdoor air temperature. 8 9 Boil Com Boiler Sensor Connect the two wires from the Boiler Sensor 082 to the Boil and Com terminals (8 and 9).
tekmar Net™ (tN2) Device 9 10 A Remote Display Module (RDM) 040 or Remote Start / Stop Module 039 can be connected to the tekmar Net™ (tN2) input. Connect the Com terminal from the appropriate tN2 device to the Com terminal (9) on the 667. Connect the tN2 terminal from the appropriate tN2 device to the tN2 terminal (10) on the 667. Note: The wires from the RDM and Remote Start / Stop Module are polarity sensitive. The tN2 device does not operate correctly if the wires are reversed.
System Pump (System Pmp 2) If a pump is connected to the System Pmp 2 terminals (17 and 18), make sure power to the pump circuit is off and install a jumper between the System Pmp 2 terminals (17 and 18). When the circuit is powered up, the pump should turn on. If no response occurs, check the wiring between the terminal and the pump and refer to any installation or troubleshooting information supplied with the pump. If the pump operates properly, disconnect the power and remove the jumper.
LOCK / UNLOCK (FACTORY SETTING IS UNLOCK) The Lock / Unlock DIP switch is used to lock and unlock the access level of the control and tekmar Net™ tN2 device. Once locked, access levels can not be changed. To determine if the control is currently locked or unlocked, a small segment representing a padlock is viewed in the bottom right hand corner of the display. When the padlock is closed, the access level cannot be changed. To change the access level, set the DIP switch to the unlocked, or down position.
667 View Menu (1 of 1) Access Level Description Range Se ct LT ion D U SE IN R S AD T V Item Field © 2009 Outdoor Current outdoor air temperature as measured by the outdoor sensor. -67 to 149°F (-55 to 65°C) E1 Slab Target Slab sensor target temperature. – – –, 20 to 110°F (– – –, -7 to 43°C) E1 Slab Current slab sensor temperature. -58 to 167°F (-50 to 75°C) B1 Status Operating status.
667 Adjust Menu (1 of 2) Access Level Description Range Actual Setting Se ct LT ion D U S IN ER S AD T V Item Field B1 Run Time The time for which a zone is operated once it has reached its melting temperature. This item cannot be viewed if a Remote Start / Stop Module 039 has been connected. 0:30 to 17:00 hr, INF (Infinity) Default = 4:00 hr E1 Add Melt The additional time for which a zone is operated once the Snow / Ice Sensor 090 becomes dry.
667 Adjust Menu (2 of 2) Access Level Description Actual Setting Range Se ct LT ion D U SE IN R S AD T V Item Field C1 Differential The differential for the snow melting system. Boil SENS = SUP AUTO, 2 to 42°F (AUTO, 1 to 23°C) Default = AUTO A C1 Boiler Minimum The minimum temperature allowed for the boiler target temperature.
667 Monitor Menu (2 of 3) Description Range LT D U SE IN R S AD T V Item Field Access Level Slab Low The lowest recorded temperature at the slab sensor since this item was last cleared. -58 to 167°F (-50 to 75°C) Mix High The highest recorded temperature at the mixing supply sensor since this item was last cleared. -25 to 230°F (-32 to 110°C) Mix Low The lowest recorded temperature at the mixing supply sensor since this item was last cleared.
667 Monitor Menu (3 of 3) Access Level Description Range LT D U SE IN R S AD T V Item Field Non-Cop The number of times that the control has been powered up since this item was last cleared. This number will increase if there is a lowering of the input voltage beyond the control’s usable range. This item can be used as an indication of the quality of the power source.
Testing the Control The Snow Detector & Melting Control 667 has a built-in test routine which is used to test the main control functions. The 667 continually monitors the sensors and displays an error message whenever a fault is found. See the following pages for a list of the 667’s error messages and possible causes. When the Test button is pressed, the test light is turned on. The individual outputs and relays are tested in the following test sequence.
Troubleshooting When troubleshooting any heating system, it is always a good idea to establish a set routine to follow. By following a consistent routine, many hours of potential headaches can be avoided. Below is an example of a sequence that can be used when diagnosing or troubleshooting problems in a hydronic heating system. Establish the Problem Establish the problem. Get as much information from the customer as possible about the problem.
667 Error Messages (1 of 3) Error Displayed Description of Error The control was unable to store a piece of information into its EEPROM. This error can be caused by a noisy power source. The control will display the error message and will continue to operate as normal. Pressing either the Menu or Item button will clear this error. The control was unable to read a piece of information stored in the ADJUST menu.
667 Error Messages (2 of 3) Error Displayed Description of Error The control is no longer able to read the mixing supply sensor due to an open circuit. In this case, the control does not operate the snow melting system. Locate and repair the problem as described in the Data Brochure D 070. To clear the error message from the control after the sensor has been repaired, press either the Menu or Item button. The control is no longer able to read the mixing return sensor due to a short circuit.
667 Error Messages (3 of 3) Error Displayed Description of Error The control is no longer able to read the water detection circuit due to an open circuit. In this case, if the control is currently in the Melting mode, the control will finish the snow melting cycle. The snow melting system can only be operated using an external melt demand, Remote Display Module 040, Remote Start / Stop Module 039 or the Start button on the control. Otherwise, the control will operate as if the Snow / Ice Sensor 090 is dry.
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Technical Data Snow Detector & Melting Control 667 Variable Speed Injection — — — — — Ambient conditions — Power Supply Relays Variable Pump Demand Sensors included — — — — — Optional devices — D 667, A 667’s, D 001, D 070, E 021, U 667. Microprocessor PID control; This is not a safety (limit) control. 3.1 lb. (1400 g), Enclosure A, blue PVC plastic 6-5/8” H x 7-9/16” W x 2-13/16” D (170 x 193 x 72 mm) CSA C US, CSA 22.2 No 24 and UL 873, meets class B: ICES & FCC Part 15.
