Thermolec is certified under CSA, CSA/US and UL standards. We also carry H-Stamp and National Board certifications for our electric boilers.

It is recommended that the minimum air flow across the elements is 300 FPM (1.52 L/S) for open element heaters and 500 FPM (2.53 L/S) for tubular/sheathed elements.

The pressure drop can be estimated by referring to the Pressure Drop Chart included in the technical notes document on our website. These values are under the guideline that the depth of the element frame is 10” (254mm).

Thermolec can provide thermostats with any given heater upon request. If a different thermostat is to be used, make sure that the output capabilities of the thermostat is compatible with what was ordered. • Active 0-10VDC signal for modulating heaters (Similar to Thermolec’s CTH-291) • Passive Thermistor output for modulating heaters (Similar to Thermolec’s DT-1040 and RT-1030) • Active 24VAC output for staged ON/OFF heaters (Similar to Thermolec’s CTH-010 or CTH-294) • Standard dry-contact thermostats for staged ON/OFF heaters.

The electronic air flow sensor was designed specifically for VAV and CAV applications where the air flow may be too low, even below the recommended air flow. This is to be used in collaboration with modulating controls.

No, only an NTC Type 3 Thermistor with a 10kΩ reading can be used with Thermolec heaters.

The PDS (Pressure Differential Switch) is a safety device used to enable/disable the heater’s operation when sufficient air flow is achieved. It closes when there is a minimum of 0.05” of static pressure. It is forbidden to bypass the PDS if it appears to be malfunctioning during operation. A chattering PDS means there are air flow issues in the application that require attention.

Yes, this can be achieved on the secondary side of the transformer. The HOT (24VAC) is usually indicated by red wiring, and the Ground (Common) is usually indicated by green wiring. We do not recommend, however, that the pull from the transformer exceed 10VA. This can cause premature failure of the transformer. It is best to inform Thermolec to size the transformer properly if it is known fact the transformer will used to power other sources.

These are terms to describe amperage values for a heater. FLA stands for “Full-Load Amps”, the maximum nominal current of a heater. MCA stands for “Minimum Circuit Ampacity”, a calculated value with a safety factor that specifies the minimum main power supply and wires. MOP/MOCP stands for “Maximum Overcurrent Protection”, the highest current rating that an electrical equipment's over-current protection devices (such fuses or circuit breakers) are permitted to handle. Note: MOP/MOCP values are not given by Thermolec. These values are to be determined by the installing electrician as per local Electrical Codes.

A spike or drop in the voltage of an electric heater will vary both the capacity (kW) and amp draw of the heater. Since an electric heater is a resistive load, and the element resistance is a fixed value, an increase in voltage will increase both the capacity and amp draw, and a drop in voltage will do the opposite for both.

Although it is not recommended to apply a different voltage to a heater already designed for a set voltage, it can be acceptable to do so if the new voltage being applied is lower than the already-designed voltage. This will just result in a lower capacity and amp draw. It is not acceptable to apply a higher voltage that the already-designed voltage. Doing this will increase the capacity and amp draw of the heater, which can cause damage to the elements and components, and creates a risk of overheating and potential fires.

SCCR is short for “Short-circuit Current Rating”, the maximum current a device or system can safely withstand. This applies to all power components in a control panel. This is a request normally required by a device that must comply with UL508A. Although Thermolec does not comply with UL508A, we can still provide an SCCR rating for heaters.

The SCCR rating given for any heater is based on the lowest value of a component in the power circuit. If there are 4 components in the power circuit, the component with the lowest value is what determines the overall SCCR rating of the given heater.

No, the humidistat must be a dry contact to enable/disable the humidifier. If the signal to the humidifier is 24VAC, a relay will need to be added to enable/disable the humidifier.

Thermolec recommends that any Acu-Steam humidifier be cleaned at least twice per season. Refer to the maintenance guide for instructions. See Section 8 – Maintenance in the Acu-Steam Manual.

Thermolec recommends that the inlet water filter be changed every 6 months to a year.

Thermolec recommends purchasing and installing the Acu-Steam Maintenance/Tune-Up kit. If the installation is brand new, verify that the unit is properly installed as per the Acu-Steam User Installation Manual. Proper installation is critical to proper operation since the unit operation is dependant on gravity.

No, using hot water to supply an Acu-Steam can cause harm to the operation of the unit.

Set the dipswitch #2 in the “RA” position for heating mode. “DA” is only for cooling mode.

If the screen show “- - “, this means there is a disconnected or broken temperature sensor. This can either be the internal sensor when the CTH-291 is used as a room thermostat, or an external duct sensor connected to terminals 7 & 8 when used as a duct thermostat.

If you see either “LO” or “HI” appear on the display screen, this means that the temperature detected for operation is outside the operating scope of the CTH-291. “LO” means the ambient temperature is below -20°C (-4°F). “HI” means the ambient temperature is above 60°C (140°F).

If the screen on the CTH-291 is completely blank upon startup, it most likely means that either there is no power connected to the thermostat, or the thermostat is defective. To function, 24VAC needs to be supplied to terminals R & C in the CTH-291.

It is recommended that the DS-600 be placed the same dimension as the width of the duct (the heater’s “W” dimension) downstream from the heater for ideal operation.