Profroid SOLO 50 Notice D'instructions page 30

 Electrical defrost
Sequences:
- Stop compressor and the fans by means of the timer or the control switch but preferably after a pump down to drain the air
cooler, but without creating a vacuum (the vapour is conductor in a vacuum). Allow the heaters to warm up.
1) The heaters are controlled by a Defrost Termination Thermostat (when ambient air temperature has been reached).
Cooling is restarted by the position of the thermostat bulb which detects the pre-set temperature which must not exceed 10°C.
The most suitable point on the coil is to be used at frost level. The clock or controller acts as a safety device for restarting
cooling, if this is not done by the thermostat.
2) The heaters are controlled by a Limiter Thermostat (when ambient air temperature has been reached).
Cooling is restarted by timer or controller reaching its time limit.
The bulb is positioned at the top of the coil, on the injection side in a free space. Insert the bulb as far as possible. In this case,
the pre-set temperature will be from 7°C to 9°C with a minimum differential (2K)
As the thermostat operates the heaters during defrost, the coil temperature evens
reduced.
Restart cooling:
1) For cold rooms at positive temperatures (for produce which must stay dry)
- Restart cooling (End of Defrost or Limiter) with icing (1 min) to avoid water splashes
- Restart fans.
2) For cold rooms at negative temperatures with wrapped or absorbent produce.
- drainage (3 to 4 min) for the material cooling of heaters.
- restart cooling with fans.
Hot gas defrost
If the hot gas defrost is selected, Profroid must be warned before realization in order to set up specific devices for this type of
defrost.
High efficiency defrost
Option package including:
- An insulated inlet hood, supplied with a heater that must be supplied with a 230V/1/50Hz.
- A defrost sock adapter.
- A defrost sock; In case of fluttering of the defrost sock a risk of detachment or tearing of the sock exists. If so make sure
to check its good assembly on the adapter or use the string on the end of the sock to adjust the outlet diameter of the air flow.
- A strap in order to assembly the sock on the adapter.
Hot glycol defrost for CO2 applications
At the engagement of the defrost cycle, the defrost coil will be filled with MEG50 at a temperature of approximately -25°C.
Because of the higher viscosity of the fluid at this temperature, the mass flow will be way lower during the initial phase of the cycle,
and will increase little by little.
In these conditions, it is important that the pump motor has enough reserve compared to the nominal operating conditions.
If the drain pan of the machine is in one part: there will be one piping system for the coil and drain pan defrost.
If the drain pan of the machine is in two parts: there will be two piping systems, one for a 1/2 drain pan, and one for the coil + 1/2 drain
pan.
The installer will have to balance the left and right defrost piping systems with a balancing valve TA (STAD first for example) per
piping system. The valves have to be installed outside of the cold room because of their minimum working temperature of -20°C.
The ajustements of the two TA valves will thus not be the same.
4- OPTIONS
HINGED FANS
Warning: pinching risk.
If the hinged fans (option) are not well fixed or badly secured, a risk of injury exists.
Make sure that the hinged fans are secured against any involuntary opening.
Before mounting, it is recommended to ensure by a visual check, that the systems to make the movable panels are in
place.
out, which allows vapour production to be