• Topic ID: id_13107370
  • Version: 3.0
  • Date: Aug 29, 2019 1:29:31 AM

Power On Sequencing

Prerequisites

Table 1 Personnel requirements
Required persons Preliminary requirements Procedure Finalization
1 Not Applicable 15-60 minutes Not Applicable
Table 2 Tools and test equipment
Item Quantity Effectivity Part number Manufacturer
Digital Volt Meter (DVM) 1 - - -
Table 3 Safety
Notice Image
  • danger
  • ELECTROCUTION HAZARD.
  • HIGH VOLTAGE PRESENT.
  • USE PROPER LOCK OUT/TAG OUT PROCEDURES BEFORE CHANGING ANY SETTINGS.
The Power On Sequence is slightly different with Discovery/Optima systems. The Main Disconnect Panel (MDP) and the Heat Exchange Cabinet (HEC) are required to power the Cryogen Cooler Compressor (CRY) and the Magnet Coldhead (See Illustration below). This document provides the installation checklist for powering on the system, and an overview description of the MDP, HEC, CRY, and the Power Distribution Unit (PDU).

Figure 1. Power Flow Block Diagram

The checklist items covered here should be done prior to starting the Installation Calibration Wizard. This checklist is to confirm proper setup.

Main Components

The following provides an overview of each main component in this sequence:

  • Main Disconnect Panel (MDP)

    The MDP contains a control power transformer that is manufactured by either GE or TEAL. It is set to 480 Vac by default. For sites with a different customer-supplied voltage, the control power transformer wiring will need to be changed. The MDP also contains a temporary jumper used to power up the system. That jumper will need to be removed. See Figure 4 and Table 5 for more details. The temporary jumper is used until the remote Emergency Off buttons are installed.

  • Heat Exchange Cabinet (HEC)

    The HEC contains a control power transformer that is set to 480 Vac. For sites with a different customer-supplied voltage, the control power transformer wiring switch will need to be changed. The HEC contains the power interface to the Cryogen Cooler Compressor (CRY). In order to power the coldhead after magnet delivery, the power cabling will need to be wired from the MDP to the HEC, and from the HEC to the Cryo Cooler. The power cable between the MDP and the HEC will be customer supplied and installed.

  • Cryogen Cooler Compressor (CRY)

    The CRY receives power from the HEC. The coldhead power cable will need to be installed to power the coldhead.

  • Power Distribution Unit (PDU)

    The PDU is setup for 480 Vac by default. For sites with a different customer supplied voltage, the power wiring will need to be changed. The power cable between the MDP and the PDU will be customer supplied and installed. The overload and short-circuit settings are dependent upon the voltage input and may need to be changed if the input voltage is changed. Not all PDUs need overload and short circuit current settings adjusted. Refer to installed PDU's manual to determine adjustment requirements.

  • Power & Gradient Cabinet (PGR)

    The PGR houses the eXtreme Gradient Amplifiers (XGA or XG2), eXtreme Power Supplies (XPS or XPS2) and the PDU. The gradient cable connections to the XGA or XG2 for each axis can be accessed here.

List of Procedures

This document includes the following Power On Checklist procedures:

  • Confirm the Main Disconnect Panel (MDP) Voltage Selection

  • Confirm the Main Disconnect Panel (MDP) Jumper Interlock has been removed

  • Confirm the Heat Exchange Cabinet (HEC) Voltage Selection

  • Confirm Internal Power Wiring to the Power Distribution Unit (PDU)

  • Confirm Overload and Short Circuit Trip Settings for the PDU Input Circuit Breaker (Pre-DVapps PDU 5140621)

  • Check the gradient cable connection at the PGR

Confirm the Main Disconnect Panel (MDP) Voltage Selection

The Main Disconnect Panel is shipped with the default voltage setting of 480 Vac.

Procedure

  1. Confirm that the control power transformer connections are in the correct configuration for your site.
    Table 4 Control Power Transformer Connection Configuration
    Incoming Voltage: GE Transformer Terminal: TEAL Transformer Terminal
    380 VAC H3 H4
    400 VAC H3 H5
    415 VAC H3 H5
    480 VAC H4 H6
  2. If the power connections are not configured properly, have the proper personnel correct the wiring. See MDP Operation and Maintenance Manual for additional details.

    Figure 2. GE MDP Control Power Transformer (H4 Input Wiring Shown)

    Figure 3. TEAL MDP Control Power Transformer

Confirm Main Disconnect Panel (MDP) Jumper Interlock Has Been Removed

The Main Disconnect Panel is shipped with the E-off jumper installed.

Procedure

  1. Confirm that the E-off jumper(s) have/has been removed. Remote E-off push buttons replace the jumper(s).
    Table 5 Location of E-Off Jumper(s)
    MDP Manufacturer MDP Jumper Terminals
    GE

    15 and 16
    TEAL

    15 and 19

    16 and 19
  2. If the jumper is not removed, have the proper personnel correct the wiring. See MDP Operation and Maintenance Manual for additional details.

    Figure 4. MDP Terminal Board with Jumpers Installed (GE MDP Shown)

Confirm Heat Exchange Cabinet (HEC) Voltage Selection

Procedure

  1. Follow the table below to confirm the transformer switch is in the proper position. See Figure 5.
    Table 6 Transformer Switch Position
    Incoming Voltage HEC Switch Position
    480, 415, or 400 Vac Up
    380 Vac Down
    note:

    The UP position is labelled "480V~" and the DOWN position is labelled "380V~".

  2. If the switch is not in the correct position, change the switch position.

    Figure 5. HEC Voltage Selection Switch

Confirm Internal Power Wiring to the Power Distribution Unit (PDU)

The PDU is shipped with the default voltage setting of 480 Vac.

Procedure

  1. Remove the small cover plate which is held in place by two screws.

    Figure 6. Input Voltage Select Small Cover (79 kVA)

    Figure 7. Input Voltage Select Small Cover (73 kVA)

  2. Confirm that the three Input Voltage Selection Terminal Blocks are wired in the correct configuration. If the power connections are not configured properly, ensure that the proper personnel correct the wiring. See PDU Operation and Maintenance Manual for additional details.

    Figure 8. Input Voltage Selection - Set at 480 Vac

Confirm Overload and Short Circuit Trip Settings for the PDU Input Circuit Breaker

Note: Overload and Short Circuit Trip Settings only apply to pre-DVapps PDU 5140621. The overload and short circuit trip settings for the Input Circuit Breaker must be set to the correct values corresponding to the input voltage.

Procedure

  1. Remove the small cover plate under the main circuit breaker.
  2. Lift open the transparent plastic cover on the lower portion of the circuit breaker to access the DIP switches controlling the circuit breaker.
  3. Confirm that the switches immediately under the letter “L” are configured correctly. The illustration below shows the position of the DIP switches for each input voltage.

    Figure 9. Circuit Breaker DIP Switch Settings (Black=ON / White=OFF)

  4. If the DIP switches are not configured correctly, ensure that proper personnel correct the DIP switches settings per the PDU Operation and Maintenance Manual

Check Gradient Cable Connection at PGR

Procedure

  1. Check the gradient cable connections at the PGR to confirm no shorts between two axis or load shorts to ground.
    note:

    Complete this section BEFORE applying power to the PGR.

  2. Ensure the following checks between points are low resistance (< 5 ohms) with a DVM in the following table.
    Table 7 PGR Gradient Coil Load Check — Ensure Same Coil
    From To Expected Value
    X-Axis XGA(XG2) – J17 X-Axis XGA(XG2) – J18 < 5 ohms
    Y-Axis XGA(XG2) – J17 Y-Axis XGA(XG2) – J18 < 5 ohms
    Z-Axis XGA(XG2) – J17 Z-Axis XGA(XG2) – J18 < 5 ohms
  3. Ensure the following checks between points are open (> 10 k ohms) with a DVM in the following table.
    Table 8 PGR Gradient Coil Load Check — No Shorts
    From To Expected Value
    X-Axis XGA(XG2) – J17 Y-Axis XGA(XG2) – J17 > 10 k ohms
    X-Axis XGA(XG2) – J17 Z-Axis XGA(XG2) – J17 > 10 k ohms
    Y-Axis XGA(XG2) – J17 Z-Axis XGA(XG2) – J17 > 10 k ohms
    X-Axis XGA(XG2) – J17 Ground > 10 k ohms
    Y-Axis XGA(XG2) – J17 Ground > 10 k ohms
    Z-Axis XGA(XG2) – J17 Ground > 10 k ohms
  4. If any of the Table 4 and Table 5 checks fail, review the installation instructions for gradient cable connections between the magnet and the PGR prior to applying power to the system.
    note:

    This check does not ensure X, Y and Z gradient load coils are connected to the corresponding gradient amplifier.

Finalization

Finalization

Select Installation Calibration Wizard checklist items that were confirmed as completed.