Carbolite Peak Series - Manual (Page 6)

Peak Ovens
6
MF15 – 3.13
3.4 Temperature Uniformity
Where accurate temperature control of the load is important, use the central part of the chamber
and place or distribute the load to allow free air circulation. Do not place loads on the chamber
floor: use the bottom shelf.
3.5 Explosive Vapours
The standard models are not suitable for drying or heat treatment applications where vapours are
released that are combustible or that can form explosive mixtures with air. For such applications
only use models supplied with the stoving and curing option.
3.6 Atmospheres
When an optional gas inlet is fitted there is a label near the inlet saying "INERT GAS ONLY". In
practice inert or oxidising gases may be used, but not combustible or toxic gases. The oven
chambers are not gas tight, so it should be understood that gas usage may be high, and that the
chamber is likely always to contain some air. Residual oxygen levels of 1% are to be expected.
3.7 Variable Speed Fan Option
When this is ordered, a variable speed control is fitted in the fan circuit. Operation of the control is
self-explanatory.
Please note that there is a minimum setting at which the fan motor starts up when the oven is
switched on. Find this setting by experiment, and mark the position on the control or front panel.
It is unlikely that a control setting of less than 50% would ever be required, as there would be very
little air flow inside the oven.
3.8 Fan Exhaust and Moisture Extraction Options
When one of these options is fitted a vent duct at the back adds 45mm to the unit depth. 25mm
free space should be left behind the vent to prevent damage. The motor and fan box and outlet vent
are on the top of the unit, adding 270mm height. The outlet vent is a 64mm o/d tube to which
suitable ducting can be connected if required.
Please note that the heater element power rating may be increased; check the oven rating label for
power and fuse requirements.
Start the extraction unit using the amber switch on the control panel; this is only functional when
the instrument switch is on.
The amount of air exhaust can be controlled by adjusting the vent control knob on the control
panel.
When the unit is turned on, there may be a drop in internal temperature before the oven recovers to
the setpoint value.
3.9 Stoving and Curing Option
The oven is fitted with an explosion relief panel and a powered exhaust fan. The exhaust fan is
physically similar to that described above.
With this option the fan runs all the time that the oven is switched on.
A pressure switch detects that there is sufficient air flow through the chamber, and prevents the
oven from heating if the exhaust fan is not working correctly. If the pressure switch does not detect
sufficient air flow, a fault light comes on and the oven is prevented from heating up.
At least 200mm free space must be left at the back and side of the oven to allow the explosion
relief panel to break out if there is a rapid build up of pressure inside the chamber.
Please note that if the stoving and curing option is fitted, there may be an increase in the power
rating of the oven. See the rating label rather than the table in section 8.1.