Grade 3 Skill Gap Analysis

Information

Engineer
Conducted on
Assessors

Fault Tree Analysis

Demonstrate how to access flagged conditions and filter to open predictive work orders.
Q: How are Predictive rules set A: Predictive rules are set by make / model as per Asset.
Q: How are CPT rules set A: CPT rule set by Merchandising list.

Compressors

Q: Explain Capacity Control for Recip Comp. Difference between CR and SU. Definition and Operation A: CR capacity regulation and SU start unloader. A: CR Energised to Unload / De-Energised to Load.
Q: Explain the different Compressor Windings A: Part Wound, Star Delta and Direct On Line, Star / Delta windings.
Demonstrate how to perform resistance check
Q: Explain how to identify if non condensable gases are present in a system and. A: Carry out a Standing Pressure Test. A: Check Pressure / Temperature at Gauge Vs Ambient Temperature. Q: How you would deal with them A: Reclaim refrigerant charge. Evacuate system. Recommission system.

Inverter (L3)

Q: What are the 2 control circuits required for an Inverter to function A: Safety Control Circuit (Start) 24v DC Internally Generated A: Speed (Run) signal 0-10v or 4-20mA
Q: What are the minimum frequency limits for a Compressor or Fan motor A: Compressor 30Hz A: Fan Motor 20Hz
Q: How is the Maximum frequency determined A: As per the specifications on the manufacturers data plate.

Communications Systems and Remote

Q: What is the RCS Default Address A: 192.168.0.101 Q: What's the typical network addresses A: 192.168.0.(150-160)
Q: What is the Carel Default Address: A: 192.168.0.250 Q: What are the typical network addresses and what are HO Numbers A: 192.168.0.(140-150) HO numbers are the case controller addresses
Q: What is the default RCS Williams Address A: 192.168.0.101 If the default gateway is connected to a network with a 255 fitted this will cause comms faults as the 255 network address it 192.168.0 100 & 101
Q: What's the difference between 232 and IP connections on an RDM Hub. A: 232 is the controller comms and IP is the network connection
Q: How is an RDM cabinet controller address set A: Its an IP addressed set at the case controller
Q: What's the Maximum cable length of 232 cables A: 15m. Q: What is the maximum length of the Data cable (IP) A: 100m

Commission Standard Shop Floor (L2)

Danfoss Q: How do you Save a data base on front end and packs A: 255 data base can be saved either with a USB flash drive or using AKA65 software A: Pack files can be saved using service tool software
Carel Q: How do you Save a data base on a pack A: Pack files can be saved either through a carel key or carel Pco software
RDM Q: How do you Save a data base on front end and packs A: Data Manager data base can be saved either with a USB flash drive or on a Laptop using internet Explorer A: Pack files can be saved using a USB flash drive or on a Laptop using internet Explorer
Q: Explain how to run an RCS Npak in back up and how to set up the back up control A: Pack is switched into back up by removing the JP2 jumper. It will control on its bit switches if set and 12v is present
Q: Explain how to run an RDM in back up and how to set up the back up control A: To run pack in back up there are 2 black switches on the mimic board this will run on its bit switches if 12v is present. Also by inverting relay 12 output.
Q: When Re-commissioning a controller how do you determine the correct parameters are used A: Manufacturers setting Sainsbury's spec information available from FBI or ASL Technical department A: SSL Commissioning Compendium (Co2)

Co2 (L3)

Q: Control pressures are typically A: LT suction 12bar - LT discharge 28bar -IT suction 28bar - IT discharge 40-96bar -Receiver 36bar
Q: PRV ratings on system are: A: LT 25bar - IT 40bar - Receiver 45bar - Discharge 120bar
Q: Explain the terminology of Pressostat 1 & 2 ,Pgc , Prec and S7 A: Pressostat 1 = Suction Pressure A: Pressostat 2 = Discharge Pressure A: Pgc = Gas Cooler Return Pressure A: Prec = Receiver Pressure A: S7 = Gas Cooler out Let Temperture
Q: Explain Co2 oil management system and control for SCM and Advansor systems. A: SCM External control SCM Teklab / Traxoil control. A: Advansor Internal controller via Pack Controller and an Optical eye
Q: How is an Oil Make up Solenoid controlled by on SCM/Advansor A: SCM is controlled via an external On/Off delay timer A: Advansor is controlled via the pack controller using an Optical eye
Q: Demonstrate knowledge of pump down process for SCM and Advansor systems. Resilience unit operation & function. A: Advansor Invert to perform shut down through 255. Demonstrate on Lap Top using AKA65 simulation. A: SCM Trip QF30. Phase fail relay supply and perform shut down through 255. Demonstrate on Lap Top using AKA65 simulation.
Q: Co2 Strainer Check. Explain how to identify pressure drop issues and rectify (Advansor) A: Measurement between Pressostat 2 and Pgc (U06)
Q: Explain process of drier core change and explain best practice guidelines. A: Valve off drier inlet, partial pump dump to empty, isolate and open bypass, vent remaining vapour safely (monitor with gauge), remove drier, heat gun to prepare drier basket, fit new drier, vac and break vac with VAPOUR.
Q: Explain Temprite filter change, how to evaluate if filter change is required, service interval and potential problems. A: Service Interval every 2 years. 0.9 bar pressure drop across Temprite. Poor oil return, low receiver level. (DI3 alarm) Pump down procedure (resilience unit operation), talk through safe controlled isolation of high pressure side, controlled venting. Replace Temprite filter, checking O’rings. Vac out / break with vapour.
Co2 Questions Test results
Grade 3 Questions Test Results