Need help to identify parts and thier functions

[Camy423]

Hello everyone, i have come across a walkin freezer at subway. Clients wants it temprature between -25c to -30c. Freezer was working fine till last week, when it started to drop its temprature they called a tec. I dont know what he did, but he said there was a leak he fixed it and charged the system with R404a. He left and said everything is fine and temprature will drop to -30c. Well this didnt happen what happen was short circuting in panel box wich damaged circuit breaker and magnet switch.

Anyway they called me now as there regular tec is not showing up. Quiet honestly i dont have prior expirience working with these freezers. I have replaced two circuitbreakers as i have them on me, i will be taking new magnit switch on monday, this will turn on my unit. Now the problem is that on compreser there are no labels indicating which refrigerant should be used. At subway they have a walkin cooler as well, so this walkin cooler have same system installed. Both compressors are same. At least they look same .the compressor installed on walkin cooler have labels and it says it R134a. What i am confused is this should i charge R134a. So far i am not able to verify which refrigerant i am suppose to use...

Any help is appreciated. Below are some pics attached.