8.0 Maintenance
The damper should be inspected after the first 6 months of
operation. Remove any accumulated
dust and dirty using a soft
brush and low power vacuum cleaner (e.g. a small battery operated
model). Thereafter; inspect and clean the damper as site condition
dictates. We recommend that inspection should take place at least
once a year
.
9.0 Warranty
The damper is supplied with a 5 year warranty when used with
Nuaire fans. The first year includes parts and labour with the
remaining period parts only. The warranty period begins on the
date of delivery. If the damper is not used with Nuaire fans the
warranty period is 12 months parts only.
This warranty is void if the equipment is modified without
authorisation, is incorrectly applied, misused, disassembled, or not
installed, commissioned and maintained in accordance with the
details contained in this manual and general good practice.
The product warranty applies to the UK mainland and in
accordance with Clause 14 of our Conditions of Sale. Customers
purchasing from outside of the UK should contact Nuaire
International Sales office for further details.
10.0 After Sales
For technical assistance or further product information,
including spare parts and replacement components, please contact
the After Sales Department.
Tel: 02920
858
400
10.0 Appendix 1. Detailed operating
sequence of CVD damper
On power up
The active LED will flash 3 times; after this the LED will be lit
continuously if the switched live signal or the CVD-PIR is active
(boost mode) and flash slowly if it is inactive (trickle mode).
The damper will drive close for 12 seconds then open for 15 seconds.
The damper will then drive close for 90 seconds to ensure it starts
its operation from the fully closed position. Some noise may be
heard during this period as the damper is driven against its end
stop!
Warning – the unit must be connected permanently to the mains
supply during normal operation. Use the switched live (SL) or the
CVD-PIR to select boost setting. If the mains switch is switched on
and off in normal operation, the noise generated during this start
up routine may become a nuisance.
2. The unit will start to measure the airflow after the initial power
on routine. If the airflow is below the minimum calibration value
(e.g. 5l/s for CVD100), it will drive open until it reaches half way
through its allowable travel (approximately 15mm from the
foam) and stop.
3. When there is a consistent airflow greater than the minimum
calibration (e.g. 5l/s for CVD100) for more than 10 seconds, the
unit will begin to operate normally. The damper will be driven
open or close depending on the measured airflow and the
relevant set point.
4. If the fan is stopped and the damper is less than half opened
then the damper will travel to half opened position and stop. If
the damper is at position beyond this, it will just stop.
This is to make sure the damper is opened when the fan restart.
The fan is considered to have restarted the conditions given in
point 3 is met.
5. The damper has a limited travel of approximately 35mm.
Therefore it is essential that the gap between the foam and
damper blade is less than 35mm to obtain full controllability
before the damper is switched on. A maximum gap of about
20mm is recommended and would be the normal gap when the
damper is delivered. Do not manually move the damper blade
beyond its operating range.
Note 1:
The CVD volume control dials were calibrated in our laboratory
under ideal flow conditions to give typical accuracies as given
in table below. These should be used as a guide to the setting
position. Site conditions may cause the calibration to drift;
e.g. bends or inlet grille being too close or multiple bends.
If this occurs; the trickle and boost set point should be
adjusted up or down as necessary to produce the desired
flowrate.
*Typical accuracies of the dampers under ideal conditions.
CVD125 …..……+/-3l/s
CVD150 ………+/-3l/s
CVD200 ………+/-4l/s
Please see leaflet 671405 for guidance on commissioning the
system and CVD dampers.
Installation and Maintenance
CVD Constant Volume Dampers
5
10. 05. 17. Leaflet Number 671638
Technical or commercial considerations may, from time to time, make it necessary to alter the design, performance and
dimensions of equipment and the right is reserved to make such changes without prior notice.
