Open Coil Electric Duct Heaters by Q'Mark
Q'Mark Open Coil Electric Duct Heaters are custom engineered to customer specification and built to order. They are available UL listed in Slip-in or flanged configurations with heavy gauge galvanized steel frame and terminal box construction. There are also NEMA 12 and NEMA 4 models available. Units include primary and secondary thermal protection and are designed for use with vertical up or horizontal airflow in either direction. Alternate constructions are available for oven heaters, round duct, bottom insert and rain tight installations. Elements are constructed using only the highest A-grade 80/20 nickel-chromium resistance wire with stainless steel terminals. Other optional construction features include recessed, dust tight or insulated terminal box, insulated flanges and protective screens.
A wide assortment of built-in control options are available. Exact, not typical, wiring diagrams are provided with each heater.
u CUSTOM ENGINEERED
u HEAT OUTPUT UP TO 2000KW
u 80/20 A GRADE RESISTANCE WIRE
u VARIETY OF CONSTRUCTION STYLES AND OPTIONS
u MANY CONTROL OPTIONS
u APPLICATIONS INCLUDE:
– OFFICE BUILDINGS
– INSTITUTIONS
– RETAIL STORES
– PRIMARY HEAT IN AIR HANDLING UNITS
– AUXILIARY HEAT FOR HEAT PUMPS
SLIP-IN HEATER
Standard and by far the most widely used because
of the ease of installation. When built-in controls are specified in a slip-in heater, they are usually mounted in the left-hand overhang. If right-hand overhang is desired, specify S dimension to be 1”, T dimension as required.
INSTALLATION
Step 1. Cut hole in side of duct 1/8” larger than heater body.
Step 2. Insert heater until terminal box covers opening.
Step 3. Secure heater in place with sheet metal screws.
FLANGED HEATER (Optional)
Consists of a slip-in heater mounted in a flanged duct section. The slip-in portion slides out without removing flanges from duct. When built-in controls are specified in a flanged heater, they are mounted in the terminal box of the slip-in portion; the frame containing the elements stays the same. The flanged duct section is increased in depth to accommodate the larger terminal box.
INSTALLATION
Step 1. Provide flanges on ends of duct matching heater flanges
Step 2. Secure heater flanges to duct flanges with sheet metal screws, so that mounting screws do not enter terminal box.
Part Number Breakdown
OPEN COIL DESIGNATION
OF Flanged (>81°F Inlet Air)
OG Flanged (80°F Max Inlet Air)
OS Slip-In (>81°F Inlet Air)
OT Slip-In (80°F Max Inlet Air)
OW Outdoor
ORS Round Duct (>81°F IA)
ORT Round Duct >80°F max IA)
OAF Alt. Flange Slip-In (>81°F IA)
OAG Alt. Flange Slip-In (80°F max IA)
MEP VOLTAGE DESIGNATION
(CONTROL VOLTAGE TO THE UNIT)
1 24V, 1Ø
2 120V, 1Ø
3 208V, 1Ø
4 240V, 1Ø
5 277V, 1Ø
MEP VOLTAGE DESIGNATION
(SUPPLY VOLTAGE TO THE UNIT & CONTROL VOLTAGE)
01 24V, 1Ø
02 120V, 1Ø
03 208V, 1Ø
04 208V, 3Ø
05 240V, 1Ø
06 240V, 3Ø
07 277V, 1Ø
08 480V, 3Ø, 3-wire
09 480V, 3Ø, 4-wire
MEP STANDARD CONTROL PACKAGES (SEE CONTROLS BROCHURE FOR PACKAGE DETAILS)
1 Contains a de-energizing magnetic operating contactor, fuses (heaters > 48 amps), & line-voltage to 24V control transformer.
2 Contains a de-energizing magnetic operating contactor, fuses (heaters > 48 amps), a line-voltage to 24V control transformer with primary fuses, & electronic step control.
3 Contains a de-energizing magnetic safety contactor, a de-energizing magnetic operating contactor per step, fuses (heaters > 48 amps), SCR control, SCR Vernier System, & line-voltage to 24V control transformer.
4 Contains a de-energizing magnetic safety contactor, fuses (heaters > 48 amps), SCR control & line-voltage to 24V control transformer.
0 Not a standard control package - user defined.
To calculate the amount of heat required in Kilowatts (KW), knowing the volume of airflow in cubic feet per minute (CFM) and the temperature rise is in degrees Fahrenheit (ΔT) that is required for the application, the required kilowatt (KW) rating of the heater can be determined from the formula: KW = (CFM x ΔT)/3160
Supply Wire & Terminal Sizing
UL requires the line terminals in duct heaters be sized to accept conductors which are rated to carry at least 125% of heater line cur- rent. Heaters are provided with properly sized terminals at no extra charge. Field supply wires must be sized to carry at least 125% of heater line current except when the heater is for space heating, is over 50 KW, and not more than 3 wires in the conduit. Under those conditions the conductors may be sized at 100% of the heater line current. Supply conductors must have insulation rated at 75°C (167°F) or higher.
Open Coil Duct Heaters
Open Coil Duct Heaters utilize the highest grade resistance wire in the manufacturing process. An iron-free, 80% nickel and 20% chromium wire has a lower operating temperature, a higher corrosion resistance, less resistance change, less sag, and a longer life expectancy than other commonly used resistance wires.
For most simple space heating applications, open coil models are a good choice. Open coil models tend to be lower KW and smaller in size than a finned tubular unit. Some of the advantages of an open coil model are:
• Element Temperature – The open coil element releases its heat directly into the airstream. As a result, the open coil runs cooler than the coil in the finned tubular element which is isolated from the air by insulation and a metal sheath. Because the heat is going directly into the airstream, the duct heats up quicker.
• Low Pressure Drop – Because of the high percentage of open space across the heater, open coil heaters have very low pressure drop as compared to finned tubular heaters. This can result in reduced fan motor horsepower and makes it possible to retrofit open coil heaters into existing systems without changing the fan motor
• Large Electrical Clearances – Generous electrical clearances between the coil and frame enable open coil heaters to withstand severe applications such as subway car heating, where voltages may exceed 750 volts.
• Smaller Size – It is normally possible to get a higher KW with open coil construction for a given face area.
Q'Mark Open Coil Duct Heaters are UL listed in the USA.
Q'Mark Open Coil Duct heaters are Made in the USA.
Call Anderson-Bolds for more information or for the Ohio or Kentucky wholesaler nearest your location.
216-360-9800 or 513-528-5680
No comments:
Post a Comment