Heater Banks | rickardair

Heater Banks

The Rickard Heater Bank is designed to be mounted in a single Section of duct, complete with Mil. Galv. single skin sheet metal or fabricated MEZ flanges. Rickard HB’s (wired to terminal step control) and PHB’s (step-less proportional control) types are available.When PHB’s are supplied, the controls are mounted in a panel on the side of the unit.

PROPORTIONAL CONTROL (PHB)

STEP CONTROL (HB)

AUTO & MANUAL OVERHEAT CUTOUTS STD.

AIRFLOW CUTOUT OPTIONAL

TEMPERATURE, 0-10V DC & 24V AC CONTROL

2 YEAR WARRANTY

SINGLE OR 3 PHASE

MLM OR STANDALONE CONTROLS

CASING & CASETTE TYPE OPTIONS

The Rickard Heater Bank is designed to be mounted in a single Section of duct, complete with Mil. Galv. single skin sheet metal or fabricated MEZ flanges. Rickard HB’s (wired to terminal step control) and PHB’s (step-less proportional control) types are available. When PHB’s are supplied the controls are mounted in a panel, usually on the side of the unit.

Heater elements are of the incaloy type with a wattage Density of 3,2 watts/cm² and are rated for still air.  The Standard unit has an auto and manual reset cut-out for overheat protection.

SAFETY

An auto and manual-reset overheat cut-out is factory wired to the triac control circuit as standard. The auto overheat cut-out is activated when the air temperature in the duct rises above 65°C (± 5°C) and the manual overheat cut-out activates at 80°C (± 5°C). Please note that overheat cut-outs have a limited lifespan and should not be relied on for long term protection.

An optional Air flow Cut-out is available as an additional safety feature. This cut-out will prevent the heaters from firing in a no or low flow condition.

 

Rickard recommends the following installation safeties:

  • The HB’s mains power should be interlocked with an airflow switch in the duct.
  • The AHU should be placed on the same circuit as the heater bank so that the heaters are deactivated when the AHU is shutdown.

A 220V Cooling fan is supplied in every Heater Banks circuit panel larger than 7.5kW.

CONTROL

Step Control (HB)

Ready for step control from contactors activated by others.

Proportional Control (PHB)

Prevents the large heating overshoots which are common with step control.

Controlled by;

  • Temperature sensor or wall thermostat.
  • 0-10V DC.
  • 24VAC pulsing.

 

MAINTENANCE

No regular maintenance is required

WARRANTY

Rickard offers a 2 year manufacturer’s warranty on its Heater Banks. Please see Terms and Conditions for a full description of our Warranty. 

 

Rickard’s Heater Banks are designed to be mounted in a single section of duct supplying the coldest zone of a building. This allows the base load to be satisfied centrally so that energy isn’t wasted on a colder zone that only represents a relatively small part of the building.

The PHB triac switching set controls the heating capacity by switching the power supply to the heater on and off.  This switching takes place over a cycle of approximately 2 seconds and always occurs at zero voltage to avoid radio interference and voltage spikes.  The “on” and “off” periods are varied in proportion to the amount of heating required, i.e. 75% of heating capacity will result in an “on”  period of approximately 1,5 seconds and an “off” period of approximately 0,5 seconds.

NOTE:

  • Every PHB must be fed from a single adequately sized contactor on the distribution board. 
  • The PHB’s mains power must be interlocked with an airflow switch.
  • Rickard recommends that the AHU is on the same circuit as the heater bank so that when the AHU is shutdown, the heaters are also inactive.
  • PHB heater banks are not normally supplied with internal insulation. Please contact a RICKARD sales representative should this be required.
  • Every Heater Bank (HB/PHB) comes with a wiring diagram included in the controls panel. If anything is unclear, please contact Rickard for support.
SELECTION

Rickard Air Diffusion is not in the practice of calculating building loads. Please size the kW rating according to your requirement.

 

 

 

STEP CONTROL (HB)

Panel mounted wired to terminal porcelain connections ready for step control from contactors activated by others.

PROPORTIONAL CONTROL (PHB)

A Rickard controller that uses a proportional control signal prevents the large heating overshoots which are common with step control.

The controller can be controlled in the following ways:

  • With a Rickard temperature controller and temperature sensor or wall thermostat, the sensor is mounted in the location required e.g. in the duct. When a temperature sensor is used, the set-point is set on the controller itself. 230V AC Single Phase or 400V AC Three Phase Power Supply options are available. Please note that the 0-10V option uses a board which needs 24V AC.
  • With a 0-10V DC signal from a sensor that is duct or wall mounted or alternatively from a central controller.
  • With a 24V AC pulsing signal.

 

SIZES

PHYSICAL DIMENSIONS

Made to fit most duct sizes.

HEATER SIZES

Single phase:

0.5 - 4kW i.e. 2x2kW. Size increments of 0.25kW’s (Standalone or MLM available)

3 Phase:

4.5kW upwards in 1.5kW increments (Standalone only). Triacs used for 3 phase are 6, 12 and 18kW. A 4.5kW Heater Banks uses a 6kW triac and goes up in 1.5kW increments from there. Rickard has produced HB’s as big as 600kW. 

 

FORM FACTOR

  • Cassette type available
  • Casing type with removable heater elements (available when sizing is practical).

CASINGS

  • Stainless Steel
  • Single skin with Fibre Cement Internal Insulation
  • Double skin with internal Fibre Cement Internal Insulation

CONTROLS

  • Air flow Cut-out (available on standalone and MLM options)
  • Wall Thermostat