TEL AFA4000/2, Installation And Operating Manual

Page: 67 / 177

AFA4000/2 Airflow Monitor / p.67
5. Loosely fit the chain over the freewheeling pulley and determine the best position for
the chain counterweight.
6. Fit the chain counterweight, using a counterweight guide if necessary.
7. When the motor, chain and counterweight are fitted manually open / close the sash
to ensure the motor drive, chain and counterweight are free running.
6.3.4 Wire and pulley drive
With the Wire and Pulley Drive, the pulley motor drives the sash wire and can accept
both single and dual sash wire systems. The motor assembly is fitted in line with the sash
wires and uses two guide pulleys and a drive pulley.
The pulley drive is ideal for new fume hoods but can be retro-fitted if a longer
replacement sash wire can be fitted.
Figure 37: Typical wire and pulley drive installation
6.3.4.1 Installing the wire and pulley drive
The motor assembly can be fitted horizontally or vertically on either side of the fume
hood, as follows:
1. Fit the motor assembly so that the guide pulleys are in line with the sash wire.
2. Run the sash wire over the first guide pulley, around the drive pulley and then over
the final guide pulley.