Wednesday, February 10, 2016

Process Ovens Over 40 years Old

Safety Updates for Older Ovens.


Most Process ovens made over 40 years ago did not include an excess temperature controller or separate heating element contactors to protect the oven from overheating if the main temperature controller or contactors fail. 
 Any ovens like this should not be used until this safety equipment is installed.  Failure to install this safety equipment could result in the oven overheating and a fire that could result in oven damage, loss of the product load, building damage and injury to personnel.

A field kit to add the excess temperature controller and separate contractors should be ordered from the MFG.

The excess temperature controller and separate contactors are now standard equipment on all Grieve ovens.  Also standard is a recirculating blower airflow safety switch to shut down the oven heat if the recirculating blower fails.  This is a pressure differential switch that senses the pressure created when the blower wheel is turning.  This switch protects the oven heating elements by preventing them from heating when air is not being recirculated over them.  A field kit for installation of the recirculating blower airflow safety switch should be purchased from the oven MFG.

When installing new safety equipment it can be a good idea to add other new electronics to the oven for better performance.  New electronics could be a digital temperature controller, programmable digital temperature controller, new thermocouples or a digital timer.  Grieve can provide a field kit to add a digital temperature controllers as well as and a field kit for a digital shut down timer. For electric Ovens new elements can be ordered as well along with pin and sleeve disconnect switches for added electrical safety for personnel. We can provide Gas meters for gas ovens to measure gas flow at the oven and shut the oven down in a dangerous situation.

Grieve's field kits include installation instructions, wiring diagram showing items to be removed, wiring diagram showing items to be added and revised wiring diagram for your records.  Our kits will be based on how the ovens were constructed when they left our factory.  If there have been changes made to the oven in the field they will not be included in our revised wiring diagram.   

Grieve will provide all parts except for standard wire, conduit and conduit fittings.  These items are better provided in the field as necessary to connect the components being added.  Conduit would only be required for the air flow safety switch as the other items are mounted in the oven control panel.

Please contact Anderson-Bolds with the oven serial number, job # and model number all of which can be found on the name plate of the oven.  We can also provide new wiring schematics for old ovens and instruction manuals.  Grieve and Anderson-Bolds want our products to be operated in the safest manner possible. 

Contact Anderson-Bolds at: