A-102-1 Electric Duct Heater Brochure - Brasch
A-102-1 Electric Duct Heater Brochure - Brasch A-102-1 Electric Duct Heater Brochure - Brasch
Step ControllersStep controllers are used to control multi-step heaters.ELECTRONIC MODULATINGSolid state electronic step controllers will switch up to tencontactor holding coils each and may be wired in series fora maximum of 30 steps. They are available with a singleinput from all commonly used thermostat input signals.The step controller automatically recycles to the full-offposition in case of a power interruption.SCRsSCR VernierSilicone controlled rectifiers (SCRs) are used to provide very close heat controland/or silent operation for critical areas such as laboratories, computer rooms andexecutive offices. They are a solid state device with no moving parts which willprovide 100% stepless and noiseless modulation through many years of troublefree service. The SCR has heat sink mounted protruding through the terminal boxto maximize convection cooling. The heat sink is electrically insulated from liveparts. Power and heat output are precisely controlled from zero to 100% in directresponse to the modulating thermostat signal (figure 25). All commonly used thermostatinput signals will be accepted by the SCR without a special interface. Asafety contactor must be used.SCR Vernier systems are used on larger KW heaters where very close heat controlis required. The SCR Vernier system employs a combination of SCR and non-SCR steps. For electric/electronic controls, a step controller energizes the non-SCR steps; for pneumatic controls, adjustable differential PE switches energizethe non-SCR steps. The system is more economical for larger KW heaters thanfull SCR control while providing the same very close heat control as the full SCRsystem. This is accomplished by satisfying most of the heat requirement throughthe non-SCR steps and then the last portion of the heat requirement is "finetuned"by the modulating SCR controller. The SCR step is nominally equal to theKW of a non-SCR step to provide an even transition between steps.All elements in the heater are simultaneously controlled, thus avoiding problemsof air stratification. Zero angle firing interrupts the full wave AC cycle only whencurrent passes through zero, minimizing radio frequency interference.8 BRASCH MANUFACTURING
ThermostatsTable 23: ThermostatsCatalogNumber Type Temp. Range Ratings Action No. StepsT-101 Room 40 - 90° F 120 - 240V Pilot 1T-102 Room 40 - 90° F 120 - 240V Pilot 2T-111 Room 40 - 90° F 24V Pilot 1T-112 Room 40 - 90° F 24V Pilot 2T-201 Room 40 - 90° F 120 - 277V Line 1T-300 Room 60 - 90° F D.C./Resistive Output Step Controller Mod.C1025 Room 60 - 90° F D.C./Resistive Output SCR Mod.T-400 Room 40 - 90° F Pneumatic Direct Acting Mod.T-401 Room 40 -90° F Pneumatic Reverse Acting Mod.T-601 Duct 60 -90° F 120 - 240V Pilot 1T-602 Duct 60 - 90° F 24 - 240V Pilot 2T-603 Duct 60 - 90° F 24 - 277V Pilot 3T-604 Duct 60 - 90° F 120 - 277V Pilot 4T-810 Duct 80 - 100°F D.C./Resistive Output Step Controller Mod.T-100-M043 Duct 0 - 180°F D.C./Resistive Output SCR Mod.TG-100M Thermostat Guard — — — —NOTE: Data subject to change without notice.BULLETIN A102-19
- Page 1 and 2: Bulletin A102-1© Brasch Manufactur
- Page 3: Ratingsand SizesYou specify it—we
- Page 6 and 7: Construction DetailsAutomatic reset
- Page 10 and 11: Special ConstructionsHeaters forDuc
- Page 12 and 13: Special Constructions (cont.)BOTTOM
- Page 15 and 16: Finned TubularSLIP-IN AND FLANGED
- Page 17 and 18: Use these formulae as rough guideli
- Page 19 and 20: How to Calculate Line CurrentsTo de
- Page 21 and 22: Wiring Diagram Control System 2Mult
- Page 23 and 24: Wiring Diagram Control System 4Tota
- Page 25 and 26: REQUIREMENT(b) Thermostats That Do
- Page 27 and 28: Express Duct Heaters 14 Day Shipmen
ThermostatsTable 23: ThermostatsCatalogNumber Type Temp. Range Ratings Action No. StepsT-101 Room 40 - 90° F 120 - 240V Pilot 1T-<strong>102</strong> Room 40 - 90° F 120 - 240V Pilot 2T-111 Room 40 - 90° F 24V Pilot 1T-112 Room 40 - 90° F 24V Pilot 2T-201 Room 40 - 90° F 120 - 277V Line 1T-300 Room 60 - 90° F D.C./Resistive Output Step Controller Mod.C<strong>102</strong>5 Room 60 - 90° F D.C./Resistive Output SCR Mod.T-400 Room 40 - 90° F Pneumatic Direct Acting Mod.T-401 Room 40 -90° F Pneumatic Reverse Acting Mod.T-601 <strong>Duct</strong> 60 -90° F 120 - 240V Pilot 1T-602 <strong>Duct</strong> 60 - 90° F 24 - 240V Pilot 2T-603 <strong>Duct</strong> 60 - 90° F 24 - 277V Pilot 3T-604 <strong>Duct</strong> 60 - 90° F 120 - 277V Pilot 4T-810 <strong>Duct</strong> 80 - 100°F D.C./Resistive Output Step Controller Mod.T-100-M043 <strong>Duct</strong> 0 - 180°F D.C./Resistive Output SCR Mod.TG-100M Thermostat Guard — — — —NOTE: Data subject to change without notice.BULLETIN A<strong>102</strong>-19
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