chillyblue
21-01-2021, 03:52 PM
Hi All
I've already written all this once but I think it disappeared so apologies if this is the second one!!
I have a air to water heat pump on a commercial premises supplying hot water at +70deg C
The system consists of two LG V5 series outdoor units feeding 4 x LG hydro boxes feeding water into a buffer tank.
I have a problem with the hydro boxes, on the refrigerant outlet of the hydro boxes (liquid line return to the outdoor units) I have had this freezing down to -13degC which froze the heat sinks on the side of the control boxes of the outdoor units and blew all of the inverter boards.
On the outlet at the hydro box is a eev which I believe should either be open or closed as if it modulates it would cause a pressure/temp drop on the liquid line causing evaporation, the outdoor units have their own eev's which were being starved due to the eev restriction at the hydro boxes, this caused a low load/poor performance at the outdoor units causing the outdoor unit heat exchangers to partially freeze.
I took the eev head off (the eev is the type with the pin Sanhua DPF 0 6.4 they unscrew, not the lift of heads) of the hydro box on the liquid line and the performance was perfect having a 40deg C temp either side of the eev the performance of the system was great no frosting on the outdoor unit heat exchangers and great performance at the hydro boxes, when i tried to get the eev head back on I had a bit of difficulty as both the pins on the head and the valve were fully extended (if anybody has any info on how to get these back together easier that would be great)
I'm assuming that either the eevs have got stuck, got dirt in them and are blocking or are not controlling properly, out of calibration and not opening or shutting properly or I have another problem I'm overlooking, I cant see why you would want the valves to act as a expansion valve when they are feeding eev's in the outdoor units???
I think the valves would be fully open when demand is required and then shut when not required.
Thanks in advance for your help
CB
I've already written all this once but I think it disappeared so apologies if this is the second one!!
I have a air to water heat pump on a commercial premises supplying hot water at +70deg C
The system consists of two LG V5 series outdoor units feeding 4 x LG hydro boxes feeding water into a buffer tank.
I have a problem with the hydro boxes, on the refrigerant outlet of the hydro boxes (liquid line return to the outdoor units) I have had this freezing down to -13degC which froze the heat sinks on the side of the control boxes of the outdoor units and blew all of the inverter boards.
On the outlet at the hydro box is a eev which I believe should either be open or closed as if it modulates it would cause a pressure/temp drop on the liquid line causing evaporation, the outdoor units have their own eev's which were being starved due to the eev restriction at the hydro boxes, this caused a low load/poor performance at the outdoor units causing the outdoor unit heat exchangers to partially freeze.
I took the eev head off (the eev is the type with the pin Sanhua DPF 0 6.4 they unscrew, not the lift of heads) of the hydro box on the liquid line and the performance was perfect having a 40deg C temp either side of the eev the performance of the system was great no frosting on the outdoor unit heat exchangers and great performance at the hydro boxes, when i tried to get the eev head back on I had a bit of difficulty as both the pins on the head and the valve were fully extended (if anybody has any info on how to get these back together easier that would be great)
I'm assuming that either the eevs have got stuck, got dirt in them and are blocking or are not controlling properly, out of calibration and not opening or shutting properly or I have another problem I'm overlooking, I cant see why you would want the valves to act as a expansion valve when they are feeding eev's in the outdoor units???
I think the valves would be fully open when demand is required and then shut when not required.
Thanks in advance for your help
CB