J&e hall fusion unit charge

[jammy23]

I've currently had to swap out the evaporator unit for a walk in freezer which the coil had leaked on. When charging the system with refrigerant r404a does the sight glass need to stay clear at all times? The condenser is a j&e hall fusion unit model:jehr-0175-b2-l-3 , I know it may sound like a daft question but the unit cycles the condenser fan to keep head pressures regulated and when the fan speeds up the sight glass drops to half full and when the fan slows to almost stopping it clears again. Obviously I'm reluctant to just keep adding as I don't want to over charge, the head pressures have been set to cycle at 230-260psi and suction pressures are also between 16-24psi. Anyone dealt with this type of condenser before and know what the sight glass should run like?

Thanks

[FaultCode]

Make sure that the freezer is down to temperature before confirming operating conditions.

Run the condenser fan at full speed and then check your superheat and sight glass.

If the fan controller is a variable speed device is sounds a bit unstable but until the system is running at design temperature things can be a bit awry.

[jammy23]

The last one I worked on I set up the same and gassed the same but even on the other I was a little unsure if the sight glass should be clear at all times or if the drop in the sight glass is just normal for these units. That unit ran down to temperature no problem and this one is coming down slowly. But I do know the previous unit used to take a while to come down. Just wondered whether the sight glass dropping was normal or whether more gas is needed.