Evolution Electric Heat Modulator CONTROLS INC. EVO/ EHM-S3

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1 Evolution Electric Heat Modulator COTROLS IC. EVO/ -S3 The allows a wide variety of ETC (External Temperature Control) devices to control an (Solid State Relay) switched electric heater assembly. Connecting a DAT (Discharge Air Temperature) sensor enables adjustable DAT control. The modulates the electric heater elements in response to a call from the ETC. External temperature controls may be a simple thermostat, or a wide variety of common heater control methods offered by building automation manufacturers. These controls may provide a simple call for 100% heat, call the heat in stages, or call the heat by analog signal. Without DAT control, the uses this call to determine the percent of adjusted heater capacity supplied to the air stream. A Capacity Limit Control (CLC) feature determines the adjusted heater capacity. Capacity Limit Control An local adjustment sets the maximum heater output between 45% and 100% of the combined installed heater s full capacity. Calls for heating proportionally set the heater output within the constraints of the adjusted capacity. The installed heater capacity needs to be reduced where the installed heater is too large for the condition space. Oversizing may be planned to address future use of the space. Or it may result from changes in usage where planned computers or other static thermal loads were removed from the space. Discharge Air Temperature Control By connecting a temperature sensor, the automatically invokes DAT control and disables CLC. DAT control modulates the electric heaters to maintain a discharge air temperature calculated from the ETC s call for heat. The includes an adjustment that sets the DAT when the ETC calls for 100% heat. This is the DAT high limit. DAT limit is addressed in ASHRAE 1 standards 62.1 and When the ETC calls for less than 100% heat, the calculates the DAT control point as a percent of the temperature span between the starting air temperature and the DAT. (The starting air temperature equals the DAT when electric heat is off). Specifications: Power: ~24V +- 20% 50/60 Hz, 10 VA, 5 W Discrete Inputs (3): 1K8 load ~24V 50/60 Hz Aux Power: 50 VA max. Analog V Input (1): V mA Add a 511Ω Resistor DAT Sensor: Output Indication 10K J type Thermistor +22V 30mA max. LED lights when relays are fired 1 American Society of Heating, Refrigerating, and Air- Conditioning Engineers, Inc. WEB (858) San Diego, CA USA Fax

2 Sequence Selector: The uses up to three jumpers to select the desired sequence. Connecting a DAT sensor automatically modifies the selected sequence for DAT control. Control Sequences: PWM & O/OFF (On/Off) : : EVO/ECM--S3 : : ETC provides one ~24V output to call a one stage heater. 2 Stage (2Stg) OUT 1=OFF OUT 1= O HEAT = 100% ETC provides two switched ~24V outputs to call each stage of a two stage heater V Signal (0-10V) : : : : : : : ETC provides a Vcontrol signal. Heat modulates from 0-100% as the signal changes from V V Signal (2-10V) : : : ETC provides a V control signal. Heat modulates from 0-100% as the signal changes from V. 3 Point Floating (FLT1) : : : ETC provides two switched ~24V outputs. One increases heat and the other decreases heat at a rate of one percent per second. When no change is called, the heater output decreases at one percent per minute as a safety precaution. OUT 1=OFF & OUT 2=OFF, OUT 1= O & OUT 2=OFF, OUT 1=OFF & OUT 2= O, OUT 1= O & OUT 2= O, 3 Point Floating (FLT2) : : HEAT = +1% / SECOD HEAT = -1% / SECOD ETC provides two switched ~24V outputs. One increases heat and the other decreases heat at a rate of one percent per second. When no change is called, the heater output remains at the value of the last call. OUT 1=OFF & OUT 2=OFF, OUT 1= O & OUT 2=OFF, OUT 1=OFF & OUT 2= O, OUT 1= O & OUT 2= O, Thermostat (Incr) HEAT = +1% / SECOD HEAT = -1% / SECOD ETC provides one ~24V output. When the output is on, heat increases at a rate of one percent per second. When the output is off, heat decreases at a rate of a rate of one percent per second. OUT 1= O OUT 1=OFF HEAT = +1% / SECOD HEAT = -1% / SECOD OUT 1=OFF& OUT 2=OFF, OUT 1= O& OUT 2=OFF, HEAT = 50% OUT 1=*& OUT 2= O, HEAT = 100% OUT 1=O& OUT 2= O, HEAT = 100% (*=O or OFF) 3 Stage (3Stg) : ETC provides three switched ~24V outputs to call each stage of a two stage heater. Binary (B2) OUT 1=OFF& OUT 2=OFF& OUT 3=OFF, OUT 1= O& OUT 2=OFF& OUT 3=OFF, HEAT = 33% OUT 1=*& OUT 2= O& OUT 3=OFF, HEAT = 67% OUT 1=*& OUT 2= *& OUT 3=O, HEAT = 100% (*=O or OFF) : : ETC provides two switched ~24V outputs to call three heating stages. Binary (B3) OUT 1=OFF& OUT 2=OFF, OUT 1= O & OUT 2=OFF, HEAT = 33% OUT 1=OFF& OUT 2= O, HEAT = 67% OUT 1=O & OUT 2= O, HEAT = 100% : ETC provides three switched ~24V outputs to call seven heating stages. OUT1=OFF&OUT2=OFF&OUT3=OFF, OUT1= O &OUT2=OFF&OUT3=OFF, HEAT = 14% OUT1=OFF &OUT 2= O&OUT3=OFF, HEAT = 29% OUT1=O &OUT 2= O&OUT3=OFF, HEAT = 43% OUT1=OFF &OUT 2= OFF&OUT3=O, HEAT = 57% OUT1=O &OUT 2= OFF&OUT3=O, HEAT = 71% OUT1=OFF &OUT 2= O&OUT3=O, HEAT = 86% OUT1=O &OUT 2= O&OUT3=O, HEAT = 100%

3 EVO/ECM--S3 Capacity/High Limit Adjust The Capacity/High Limit adjust has a visual scale to provide a coarse indication of the setting. A precise adjustment can be made using a voltmeter and the chart below. Insert the voltmeter probes into the Com and Tcal test holes in the PC board. Make sure the probes do not touch any metal surface under or behind the mounted board. Adjust to the charted voltage that corresponds to the desired setting. If there is no temperature probe installed, set the Capacity limit to achieve the desired reduction in heater capacity. Set adjust to 100% if the application does not require the capacity limiter. If a temperature sensor is installed, use the appropriate F or C chart above to find the corresponding voltage for the desired High Limit (maximum discharge air temperature).

4 EVO/ECM--S3 Mounting Mount the control inside a metal control cabinet or enclosure. Fasten the control mounting posts to an earthed metal surface. Mounting posts are 3/32 /2.38mm I.D. Use #8 flat or oval head screws or aluminum blind rivets through the two metallic mounting posts. The countersink taper forces a good earth connection between the mounting post and the PC board. Solid State Relays Select zero crossing turn on/turn s sized for the connected heater current and ambient conditions. Mount s on heat sinks sized using manufacturer s criteria. To maintain heating system efficiency, heat generated by the s should be drawn into the heater s inlet air. Where possible, mount the heat sinks in or near the heater s inlet airstream. Use an for each phase, and multiple s when required to accommodate large heater loads. Wiring Wiring strips with 250 mil TAB connections provide easy connection for automated factory wiring, and a sensor connector with strand capturing screw locked terminals provides low resistance and easy on-site sensor connection. Power the from a ~24V class II low voltage power source. Connect the earthed side of the power source to the s neutral connection. The passes up to 40 VA from the ~24V Xfmr connections to the ~24V Aux connections. This feature allows easy connection of a field installed ETC device. Connect the coils in parallel. The can provide up to 30mA to drive multiple s. Connect an isolated flow proof device contact in series with the s coil circuit. A 1K8Ω resistor may be placed in parallel with the s if the contact needs increased current to insure reliable signaling. Open collector type solid state switching may also be used V input is single ended, so neutral and common are internally connected. L 1 Phase ~120V 3 Phase ~277V 1 Phase 2 Wire 1 Phase 3 Wire 3 Phase Y ~24V calls are optically isolated and share a common, isolated connection. Isolated common (icom) can be connected to neutral or ~24V of the supply powering the. Or, equipment having its own dedicated power source and ground may be connected without conflict. Using the isolated ~24V calls, one EHC can connect to multiple terminal units in the same zone. And a DAT sensor can be connected to the in each terminal unit providing individually adjustable high limits. L3 3 Phase Delta L3

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