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www.ves.co.uk
ecovent
Heat Recovery Units
Con nued
On
Ecovent /-E
units, an electric heater ba ery (EHB) will be installed. Supply to the heater
should be 1Phase or 3Phase with separate neutrals; confirma on of this can be found on the unit
nameplate. Cables should be of silicone rubber, fibreglass or of a similar high temperature
insulated type and be installed to current
I.E.T. Regula ons
, ensuring a sufficient earth connec on
to the terminal provided. Care should be taken not to overstrain the terminal pillars as this may
permanently damage the elements.
The heater is fitted with a manual-reset high temperature cutout with normally closed (NC)
terminals and is set to break if the duct temperature rises above 130 °C.
It is important that the cutout is connected to the safety circuit so the heater is isolated in the
event of overhea ng caused by airflow failure.
The electrical supply must be isolated before a emp ng to reset the manual cut-out and should
be given sufficient me to cool. For further informa on regarding electric heaters please see
VES Ref. ID431
.
If a speed controller is fitted to the system, it must not stop the fan independently of the control
system, or allow airflow to fall below the stated volume on the electric heater ba ery. Suitable
speed controllers without on/off switches are available from VES Andover.
Coils should be piped according to any relevant local codes of prac ce. Where threaded
connec ons are supplied, the only approved method of join ng method is by use of Boss white
and hemp. The thread fitted to the coil is to be supported at all mes whilst making joints. All
external piping is to be supported independently from the coil. Fluid filters are recommended.
It is important that water and steam coils are protected against damage from extreme weather
condi ons during the win ter season. If the water is allowed to freeze in the coil system,
damage may occur poten ally burs ng pipes and resul ng in emergency problems.
Fit ng a frost thermostat at the unit inlet and ensuring that boilers run con nuously in low
ambient temperatures can help to prevent this.
Hea ng coils do not cool immediately when the hot water supply is cut off. The residual heat
must be dissipated to avoid damage. The con nuous running of the fan a er shutdown
resolves this, by opera on of a run-on mer.
The recommended length of run-on is
2 minutes minimum
.
On
Ecovent
/ -W
units, a Low Pressure Hot Water (LPHW) coil will be installed. The coils are
normally suitable for LPHW at 80 °C flow and 60 °C return temperature (see the unit outline
drawing for confirma on). LPHW coils are supplied as standard with an air vent and drain plug
located on the pipe work immediately adjacent to the coil connec ons on the AHU. The air vent
should be at the highest point, with the drain at the lowest. The coil should be regularly vented so
as to avoid poten al air locks, resul ng in a fall off of duty.
Typical LPHW Coil
Fig.
12
Cau on
Coils
Electric Heater
Ba eries
Cau on
LPHW Coils
Flow
Return
Cau on
It is recommended that a check be made as to
whether any treatment is required to the water
supply for preven on of corrosion and scaling of
the equipment. Informa on regarding the necessary
ac on to be taken can be obtained from the relevant
Local Water Supply Authority.
The unit will have been supplied with connec ons
either le or right-hand side looking in direc on of
airflow. Please see order acknowledgement for
confirma on of this handing. Should you need to
alter this please consult VES as unit adjustment may
invalidate your warranty.
Airflow
Installa on
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