ELF (B)
4.15 Power Adjustment
The furnace control system incorporates electronic power control, including a “power limit”
parameter that is used to reduce the effective voltage to 208V (or 104V); the values of the power
limit
OP.Hi
parameter for different voltages are as follows:
voltage: 100
200
208
110
220
115
230
120
240
ELF 11/6B &
ELF 11/14B
OP.Hi:
100% 100% 89% 81% 75%
To alter the power limit
If the actual supply voltage is higher than the voltage on the rating label or the voltage for which
the furnace was last set, then please perform the following operations quickly and immediately
after switch-on. (Alternatively, temporarily reduce the temperature setpoint to zero to prevent
heating.)
Press
Page
until
oP
(output list) is displayed. Press Scroll
4
until
OP.Hi
(Output High) is
displayed. Press Down
T
or Up
S
once to display the value of
OP.Hi
(it is good practice to write
down the original value).
To alter the parameter to the desired value use Down
T
or Up
S
.
Caution:
Do not increase the power limit value to a value above the correct level for the supply
voltage. The heating elements could burn out, or a fuse could blow.
Note that setting the power limit to zero prevents the furnace from heating.
4.16 Control at Low Temperatures
If the furnace is to be used at temperatures much lower than its design maximum, control stability
may be improved by reducing the power limit.
Example: It is desired to run the furnace at 300°C. The normal control settings can be expected to
cause excessive overshoot as the furnace reaches temperature. Try a setting of 40%, which should
greatly reduce this overshoot. Experiment may be required to achieve a good result; avoid power
limits below about 30%, as control accuracy falls off at such levels. Note that setting the value to
zero prevents the furnace from heating.
5.0
12
MF01
Summary of Contents for ELF 11/14B
Page 6: ...ELF B 4 0 6 MF01...
