Carbolite EZS Series - Manual (Page 24)

E range
24 MF65-1.01 MF65-1.00
8.3 Power Settings & Adjustment
The furnace control system incorporates electronic power limiting. The power limit parameter
OP.Hi is accessible to the operator, and must be used to match the furnace to the actual supply
voltage. All models covered by this manual are fitted with either 104V or 208V elements and are
designed for use over the range of voltages 100V -110V or 200V-240V, the power limit parameter
is set accordingly. These models may be relocated safely to a different voltage within the range.
Note also that the E-range furnaces are designed for optimal temperature control in the range
500°C to 1200°C. Below this temperature range some temperature instability may be observed
and the controller may overshoot its set point temperature by more than 20°C. Temperature
stability and setpoint temperature overshoot can be improved by setting a suitably small ramp rate
and/or reducing the power limit setting for OP.Hi.
The power limit settings for OP.Hi depending on the voltages and temperature ranges are given in
Table 8-4.
Table 8-4. Power setting OP.Hi for actual electrical power supply voltage.
Supply Voltage 100V 104V 110V 200V 208V 220V 230V 240V
OP.Hi Setting
for500°C to 1200°C
100 100 93 100 100 93 85 78
OP.Hi Setting for
100°C to 550°C
33 33 31 33 33 31 28 26
Power Adjustment -Set the Heater Switch to Off to prevent heating while adjusting the power
limit. Refer to the separate controller manual supplied with this furnace to alter the value of
OP.Hi to the correct value as shown in Table
8-4 , (it is good practice to write down the original
value). Note if a too high a setting is made for a given voltage then this could result in the
elements burning out, or a fuse could blow.
9 SPECIFICATIONS
-Carbolite reserves the right to change specifications without notice.
9.1 Models covered by this manual
EHA/EST models – horizontal single-zone tube furnaces with controls in integral base.
EVA/EVT models – vertical single-zone tube furnaces with controls in separate base.
EHC/EZS models – horizontal 3-zone tube furnaces with controls in integral base.
EVC/EVZ models – vertical 3-zone tube furnaces with controls in separate base.
EST/EVT/EZS/EVZ models – are of a split tube furnace design.
All models have cylindrical elements with wire formed in the surface of the insulation material.
All models can accept work tubes up to a maximum outside diameter of 60mm.
All models have a maximum operating temperature of 1200°C (1100° continuous).
Model names are of the type “EHA 12/300B” where 300 is the heated length. Sizes range from
150-600mm heated length (EHA/EVA/EST/EVT) or 450- 600mm (EHC/EVC/EZS/EVZ).
Table 9-1. Recommended work tube lengths.
Heated
Length(mm)
Max.
Power(W)
Standard work
tube length
(mm)
Extended
work tube
length (mm)
150 750 300 600
300 1480 450 750
450 2000 600 900
600 2540 750 1050
Work tube adaptors, extended work tube supports, insulation plugs, and gas/vacuum end seals are
available from Carbolite for work tubes with outside diameters of 32mm, 46mm and 60mm.