Introduction; Assembly And Installation; Electrical Connection; Start-Up - Velp Scientifica DLH Manual De Instrucciones

1. Introduction

The DLS and DLH overhead stirrers with electronic speed control and advanced safety features are able to satisfy the most
diverse needs of the laboratory in terms of both viscosity and volume. The chuck is keyless and ensures a secure and easy-
to-fit mount for stirring shafts of up to 10mm in diameter. The stirring speed is electronically controlled. The shaft bearings
and belt drive ensure silent running. The stirring time is controlled electronically, values of up to 999 minutes and 59
seconds can be set and the time remaining displayed on the LCD. The relative torque value can also be displayed.
4- Display
2- ON/OFF switch
3- Control knob

2. Assembly and installation

Check the integrity of the unit after unpacking. The box includes:

Overhead stirrer

Instruction manual

2.1 Electrical connection

After unpacking the instrument, place the unit on the laboratory bench. Before connecting the instrument to the power
supply, make sure that the values on the rating plate correspond to those of the power supply.
Ensure that the socket and the relative cut-off device conform to current safety norms and are easy to reach.

2.2 Start-up

Assemble the shaft using the Allen head screw. Fasten the instrument securely to the support rod (A00001300) with the
double clamp (A00001301). Secure the receptacle using the ribbon clamp (A00001302) to avoid damage.

3. Operating controls

After a few seconds the instrument model and the software version will appear on the display. When the instrument is in use
the graphic display shows the real chuck speed (rpm) and the set speed (rpm set). Speed and time functions are controlled
by an encoder. Turn the encoder knob to select stirring speeds of from 50 to 2000 rpm. Press the encoder knob to activate
the timer and turn the knob to select the stirring time. Stirring times of up to 999':59" can be selected. Press the encoder
knob to start count-down. At the end of the set time stirring stops and "END" will appear on the display.
NOTE: the speed setting is saved when the instrument is turned off or if there is a power failure. When the instrument is
turned on again, the value flashes for approximately 8 seconds before stirring starts. During this time the speed setting can
be changed using the stirring speed knob.

3.1 Torque indicator

Keep the encoder knob pressed for 3 seconds to display the torque trend value, e.g. the value in Ncm of the effective torque
on the stirring shaft. To reset the torque value and measure the relative torque, keep the knob pressed for 3 seconds.
NOTE: The torque value indicated is not an absolute value. The reading indicates the variation in the torque value
compared to a set value defined by the operator. The most precise torque trend values are obtained once the instrument
has reached the optimum working temperature. Optimum time 10-15 minutes.

3.2 Overload protection

The current and voltage are electronically limited in order to safeguard the motor and the electronic parts against electric
surges. In the event of abnormal conditions arising the unit shuts down automatically.
Over Load Current surges
The stirrer can compensate for eventual current surges for a limited period of time; in this case
corner of the display. If the situation persists, the speed of the motor is gradually reduced, when a speed of 0 is reached the
unit shuts down.
Over Curr Rpm error
This error occurs if the chuck is accidentally blocked or if the number of revs exceeds the max. permitted value.
Over Temp Temperature error
This error occurs if the unit is used for heavy-duty work for prolonged periods of time and at an ambient temperature that
exceeds the max. permitted temperature. Before resetting the instrument allow it to cool down.

Allen key

Allen head screw
5
1- Chuck
Fig. 1

Shaft

Power suppy cable
appears in the top rh
EN