Top-Loading OvensTop-Loading Ovens

Top-Loading Ovens

  • Grieve - LA-550, LA-700, LA-850, LA-1050 and more
  • Uniformity at 100°F below maximum temperature
  • Rise Time in minutes to 100°F below maximum temperature
  • Tests run with empty oven and minimum exhaust

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For annealing, preheating, baking or any other heat processing where overhead handling equipment is used.


Full opening door exposes entire work space for easy loading.  Ideal for severe service applications — load capacities up to 4000 lbs .

Outside Dimensions

  • All Models: Control panel overhang 9″ right side.
  • LA & LC Models: Blower motor overhang 19″at rear.
  • LB& LD Models: Blower motor overhang 19″at right side (26″ on 7-1/2 HP).
  • LA & LC Models: Additional height with door open 58″.
  • LB& LD Models: Additional height with door open 70″.
  • Gas Models: Burner overhang 15″ left side; LA & LC Models right side; LA & LC Models rear.

Operating Characteristics

  • Accuracy as percent of controller span
  • Uniformity at 100°F below maximum temperature
  • Rise Time in minutes to 100°F below maximum temperature
  • Tests run with empty oven and minimum exhaust
  • Performance will vary with load and application

Certifications

  • UL Listed Control Panel
  • Meets the Requirements of the Following Standards:
  • NFPA 86 (Standard for Ovens and Furnaces)
  • NFPA 70 (National Electric Code)
  • FM (Factory Mutual
  • OSHA

Caution:

  • When processing combustible material fire protection should be considered
  • Not for use with flammable solvents or vapors. Other models available for these applications

Safety Equipment

* Adjustable manual reset excess temperature interlock to turn off heat on malfunction of main temperature controller

* Recirculating blower air flow safety switch to turn off heat on loss of recirculated air flow

* Electrical interlock shuts off heat if power to recirculating blower is interrupted

Electric Heat Includes

  • Separate heating element control contactors to turn off heat on malfunction of main control contactors

Gas Heat Includes

  • Modulating burner for 1000 BTU per cubic foot natural gas at 6” water column pressure – propane available. Inlet 1” NPT (1-¼ “ NPT above 350,000 BTU/hr input)
  • Automatic pre-ignition purge period to clear accumulated gas or fumes
  • Push button electric ignition
  • Microprocessor based electronic flame safeguard protection to continuously monitor flame and close gas valves if flame is not present
  • 325 CFM (650 CFM at 800,000 BUT/hr input) powered forced exhauster to provide combustion venting
  • Exhauster air flow safety switch to close gas valves on loss of venting
  • Two pilot valves to guarantee gas flow to pilot can be stopped
  • High and Low gas pressure switches to confirm safe operating pressure range
  • Two main burner safety shut off valves with valve seat position indicator to assure gas flow to main burner can be stopped
  • Proof of closure switch on one main valve to prevent igniting pilot unless main valve is closed
  • Leak test station at each pilot and main burner valve to allow testing for leakage through valve

Controls

  • Digital temperature controller
  • Motor control push buttons and on-off heat switch
  • LED pilot lights
  • 5 kA short circuit current rating (SCCR)

Construction

  • Choice of

* Electric or Gas heat

* 208 volt, 230 volt or 460 volt, 3-phase, 60 HZ – other input power available

  • Air operated, heavy duty door supported by steel shaft and bearings
  • ¼” steel plate top prevents loading damage
  • Wear bars at sides of work space to protect walls and duct work
  • Reinforced floor with removable grate to distribute loading across floor
  • All welded construction
  • Durable, electrically isolated, Incoloy tubular heating elements
  • Heat source located in heat chamber to prevent radiant heating
  • High pressure recirculating blower
  • Full coverage supply and return duct work with adjustable opposed louvers
  • Adjustable fresh air intake and 4” diameter (6” on Gas Heat) exhaust outlet damper
  • Insulated with 10 lbs per cubic foot density rockwool insulation
  • Aluminized steel interior
  • Slip flashing at doorway to allow inner oven to expand without affecting door sealing
  • Aluminized steel exterior with Trilite Green enamel finish
  • 1050⁰F models include 2” refractory ceramic fiber insulation on 16 gauge aluminized steel interior walls, 16 gauge 304 stainless steel heat chamber walls and stainless steel recirculating blower
  • Brushed stainless steel control panel face
  • Fully assembled and factory tested for temperature uniformity

*** CAUTION:  Ovens processing combustible material are required by National Fire Protection Association 86 Standard for Ovens and Furnaces (NFPA 86) to have a fire suppression system.  If flammable solvents or vapors are present in an oven, OSHA requires conformance with NFPA 86 Class A Oven requirements.  A powered forced exhauster and other non-standard safety equipment must be added.

LA-55036" x 36" x 36"2759" x 87" x 52"550°F1,5001 ½15132,0006"±0.3%±6°F38242,280 lbs
LA-70036" x 36" x 36"2761" x 89" x 54"700°F2,000220200,0007"±0.3%±8°F44262,795 lbs
LA-85036" x 36" x 36"2763" x 93" x 56"850°F3,000230350,0008"±0.3%±10°F57274,120 lbs
LA-105036" x 36" x 36"2769" x 97" x 60"1,050°F4,000340350,00010"±0.3%±12°F60335,865 lbs
LB-55072" x 36" x 36"54121" x 59" x 52"550°F2,4501 ½30350,0006"±0.3%±6°F30224,665 lbs
LB-70072" x 36" x 36"54123" x 61" x 54"700°F3,300240350,0007"±0.3%±8°F35195,585 lbs
LB-85072" x 36" x 36"54127" x 65" x 56"850°F4,000360400,0008"±0.3%±10°F47267,320 lbs
LB-105072" x 36" x 36"54131" x 71" x 60"1,050°F5,000580600,00010"±0.3%±12°F52248,475 lbs
LC-55048" x 48" x 48"6471" x 99" x 64"550°F2,4501 ½30350,0006"±0.3%±6°F35184,995 lbs
LC-70048" x 48" x 48"6473" x 101" x 66"700°F3,300240350,0007"±0.3%±8°F40205,915 lbs
LC-85048" x 48" x 48"6477" x 105" x 68"850°F4,000360400,0008"±0.3%±10°F52287,855 lbs
LC-105048" x 48" x 48"6483" x 109" x 72"1,050°F5,000580600,00010"±0.3%±12°F57269,005 lbs
LD-55096" x 48" x 48"128145" x 73" x 64"550°F4,200360400,0006"±0.3%±6°F24147,445 lbs
LD-70096" x 48" x 48"128147" x 77" x 66"700°F6,000580600,0007"±0.3%±8°F27168,880 lbs
LD-85096" x 48" x 48"128159" x 83" x 68"850°F7,8005100700,0008"±0.3%±10°F462511,660 lbs
LD-105096" x 48" x 48"128163" x 91" x 72"1,050°F10,0007 ½120800,00010"±0.3%±12°F523014,740 lbs