How does a generator produce electricity?
Uses mechanical energy of rotor to induce movement of electrons in stator windings, producing alternating current.
A current is applied to the armature via commutators and brushes. A mechanical prime mover rotates the armature within the stator. The combination of magnetic fields produced by the armature current and the movement created by the prime mover creates the requirements for current to be generated on the field windings.
Define the following power redundancies: N+C
What is necessary plus a catcher (zone defense).
What equipment does the Mechanical Service Distribution Board (MSDB) serve?
ER Exhaust Fans
DH Exhaust Fans
DH Air Handlers
Generator
ICW Pumps
MV Switchgear
Discuss the expected response for the following alarms: air handler sump pump failure
HOA to off. Open Main disconnect. Inspect for tripped breakers or blown fuses. Before turning unit OFF, check status of motor protection overload; if it is OPEN and water level is above the low level switch, try re-energizing the pump by turning ON the motor protection switch. If the pump overload triggers again, there is likely damage to the pump, or pump wiring.
What equipment does the House Service Distribution Board (HSDB) serve?
ER Exhaust Fans
ER Air Handlers
DH Exhaust Fans
DH Air Handlers
Generator
ICW Pumps
HPP Panel
What is the DC Power Equation?
P=I*V
Discuss the expected indications and response to the following casualties: Generator over speed condition.
Escalate to On-all Manager, call the FOC and get a TT cut, notify Gen team. Await permissions for actions or until qualified engineer/ tech arrives on site to assess.
List of reasons to engage teams IE controls, FE, ATS team, Gen Team, ETC.
Controls: Emergent controls issues that cannot be solved utilizing the controls troubleshooting wiki.
FE: Tripped breaker that exceeds 32 amps. If it's urgent outside of normal business hours, cut a sev 2.5 ticket and they'll address first thing in the morning.
Maintenance teams: Contact for support in instances where specialized equipment is alarming and you've exhausted all resources in mitigating.
What do the LEDs on the front panel of the ATSPSU-BBC indicate?
LEDs are used to indicated source availability, which source is currently supplying power to the loads, and indication of a fault.
Discuss how a basic PID loop works
A PID loop, or Proportional-Integral-Derivative loop, is a feedback control loop that uses three mathematical terms to adjust a control system to minimize error between a desired setpoint and a variable.
• Proportional: Produces an output value that is proportional to the current error value
• Integral: Proportional to both the magnitude and duration of the error, which is important for long-term accuracy
• Derivative: Computed based on the rate of change of the error, which can help predict future error
Basic operation of a PID loop is as follows:
• Calculate error: The PID loop calculates the error value by comparing the measured variable to the desired setpoint
• Adjust control variables: The PID loop uses the error value to adjust control variables to minimize the error
• Repeat: The output is measured again, and the process is repeated.
What is a PQM? What is its relationship with the AMCOP?
Power Quality Meter is a device suitable for monitoring and recording of power quality. It measures, monitors, and records harmonics, sags, swells, flickers and other power quality parameters.
At Who Made Who (WMW) sites, when the Amazon Change-Over Panel (AMCOP) receives an input from the upstream power quality meter indicating excessive (>12%) vTHD on the utility source, AMCOP initiates and completes a transfer to generator, and then auto-fails.
Explain the sump level float switches and their use
Low water level: when reached, fill solenoid opens to fill tank. Pump will de-energize to prevent overheating.
Operational level: Pump energizes for evaporative cooling.
High level: When reached, drain solenoid opens to drain excess water. Fill solenoid de-energizes.
Answer the following questions that pertain to “dry” pre-action sprinkler systems: Discuss the temperature ratings of the glass bulbs
|
Max Ceiling Temperature oF (oC) |
Temperature Rating oF (oC) |
Temperature Classification |
Glass Bulb Colors |
Color Code |
|
100 (38) |
135-170 (57-77) |
Ordinary |
Orange or Red |
Uncolored or Black |
|
150 (66) |
175-225 (79-107) |
Intermediate |
Yellow or Green |
White |
|
225 (107) |
250-300 (121-149) |
High |
Blue |
Blue |
|
300 (149) |
325-375 (163-191) |
Extra High |
Purple |
Red |
|
375 (191) |
400-475 (204-246) |
Very Extra High |
Black |
Green |
|
475 (246) |
500-575 (260-302) |
Ultra High |
Black |
Orange |
|
625 (329) |
650 (343 |
Ultra High |
Black |
Orange |
Describe what will happen If we are on generator and power becomes unacceptable.
10 Second Gen Source Loss timer
If utility if available: Gen Breaker Open, 2 Second Open Transition Time Delay, Utility Breaker Close. Generator 5 minute cooldown.
If utility is not available: 90 second dead bus timer, ATC transfer to Catcher lineup
Explain the different ways to switch the generator to automatic controls
At EMCP: Reset (if E-stopped, pull out E-stop) > AUTO button
At AMCOP: AMCOP > mode selector > AUTO > Generator start > OFF
Describe the function of the following components: Rectifier
UPS components which contain the equipment and controls necessary to convert input AC power to output DC power, accomplished through the use of diodes.
How does the FLoRES work?
FLoReS communicates between adjacent protection relays in loops to automatically isolate electrical faults within 5-10 cycles and restore voltage to the unaffected sections within seconds. Fault indication is via 2 Feeder Protection Relays or 1 Transformer Protection Relay.
Describe how the air handler responds to a loss of BMS connectivity
The Air handler will default to HAND operation and determine its own mode of operation
Describe how the ATSPSU will respond to a loss of power without a BBU.
If primary power is lost, rack will transition directly to catcher. Alarm will generate due to removed battery.
What is Kirchhoff’s Current Law?
Kirchhoff's current law states that the current entering any node/junction is equal to the current leaving that node/junction.
In Series: Current is constant. (Itotal=I1=I2...)
In Parallel: Current is additive. (Itotal= I1+I2...)
Discuss the expected indications and response to the following casualties: USB main utility breaker failing to open when commanded
AMCOP will go into AUTOFAIL.
If utility is available, load remains on utility. Verify loads (racks and mechanical) are operating normally. Reset AUTOFAIL.
If utility is unavailable, verify loads (racks and mechanical) transfer to alternate power supply.
For sites equipped with a USB catcher system, verify Deadbus timer is fulfilled and ATC transfers load to 480V Catcher. Once load stability has been validated, escalate.
Describe what an arc flash is?
An arc flash is the intense light and heat produced by an electrical arc.
This violent release of energy at extreme temperatures can be a source of damage to equipment, personnel injury, and/or death.
What is TPVR and when is it required?
The Two Person Verification Rule (TPVR) is a human performance tool used to ensure correct action is taken during manipulation of components by using a performer and verifier to independently verify each step of a task is completed safely and successfully.
TPVR is used for critical activities which are not subject to the Critical Switching Standard such as low voltage switching, valve operation, and rack events. TPVR may also be requested to be used by management for situations that are not specifically called out by the guidelines.
Roughly how long can your UPS last on batteries at full design load?
Estimated time at full load is 6-12 minutes.
If there is a breakdown in the escalation chain, what actions should the EOT take to escalate
Follow the escalation wiki. Continue contacting the next person on the chain until you speak to someone.
Discuss the difference between severity/tier levels and the time requirements to resolve each
1. Business Critical Function Down: Use this if the issue is a major issue that affects many customers (in other words, a critical service is currently offline or can’t be accessed by anyone). This severity will cause an immediate page of the first person in the resolver group for the CTI you’ve chosen.
2.Business Critical function impaired: Use this when there’s a critical feature of a service that is not working or is producing errors. This severity will cause an immediate page of the first person in the resolver group for the CTI you’ve chosen. 2.5. Business Critical Function Impaired: This is known as a “business hours sev 2”. It’s considered the same as a severity 2 ticket, but only during normal business hours. This severity will cause a page of the first person in the resolver group for the CTI you’ve chosen, but only during normal regional business hours
3. Group Productivity impaired: Use this for issues that affect a potentially large number of users but that doesn’t need to be resolved immediately.
4. Individual Productivity impaired: Use this when an issue is preventing you from working effectively, but that may not affect other users.
5. Productivity not immediately affected: Use this when the issue is a question about a service or if the issue isn’t immediately affecting your productivity nor anyone else’s. Severity 5 tickets are the only level that won’t cause a rotation of resolver group members when an SLA expires.
Explain the different breaker rack out positions (connected, test, disconnected, and withdrawn)
Connected: Power (Primary), Control (Secondary/Auxiliary) circuits, and ground are connected, breaker is racked in and fully operational.
Test: Power (Primary) circuit is disconnected with Control (Secondary/Auxiliary) circuit and ground connected, breaker is operational for offline testing and safety.
Disconnected: Power (Primary), Control (Secondary/Auxiliary) circuits are disconnected, ground is connected. Breaker is partially racked out offline.
Withdrawn: Power (Primary), Control (Secondary/Auxiliary) circuits, and ground are disconnected, breaker is fully racked out and offline.
Discuss the expected indications and response to the following casualties: USB main generator breaker failing to close when commanded
AMCOP will go into AUTOFAIL.
If utility is available, load retransferred to Utility. Verify loads (racks and mechanical) are operating normally. Reset AUTOFAIL.
If utility is unavailable, verify loads (racks and mechanical) transfer to alternate power supply.
For sites equipped with a USB catcher system, verify Deadbus timer is fulfilled and ATC transfers load to 480V Catcher. Once load stability has been validated, escalate.
What is Kirchhoff’s Voltage Law?
Kirchhoff's voltage law states that the sum of all voltages in a closed loop equals zero.
v1 + v2 + v3 + v4 = 0
In Series: Voltage is additive. (Vtotal= V1+V2...) In Parallel: Voltage is constant. (Vtotal=V1=V2...)
Discuss the expected indications and response to the following casualties: USB main generator breaker failing to open when commanded
AMCOP will go into AUTOFAIL.
If generator is available, load remains on generator. Verify loads (racks and mechanical) are operating normally. Reset AUTOFAIL.
If generator is unavailable, verify loads (racks and mechanical) transfer to alternate power supply.
For sites equipped with a USB catcher system, verify Deadbus timer is fulfilled and ATC transfers load to 480V Catcher. Once load stability has been validated, escalate.
Discuss the expected indications and response to the following casualties: Generator low voltage output.
Basler relay will read low voltage (10% discrepancy) and will perform an open transition back to utility or put the line-up on battery if utility is unavailable at which point DCEO could put the entire line-up on catcher via the ATC 600 to prevent exhausting all battery power.
List the control power sources for the USB and PDP
Utility, Generator, HUPP and associated UPS.
OPTDC: Utility, Generator, CUPP A, and CUPP B,
What is the purpose of the catcher distribution system?
To provide alternative power to critical load in the event the primary source(s) are not available.
Define the following terms as it relates to the Generator: Stop Mode
A manual mode that emergency stops the generator without a cool-down period
How does a transformer work?
A transformer produces step changes in voltages between a primary and secondary winding.
Each side of the transformer consists of electrical windings wrapped around an iron core. The magnetic field of the primary winding induces a voltage on the secondary winding and produces current. The current produced on the secondary winding is proportional to the difference in number of coils/turns from primary to secondary.
Define the following terms as it relates to the Generator: Auto Mode
A mode where the generator will stand by until called upon automatically by AMCOP where it will run until AMCOP shuts it down
Discuss the expected indications and response to the following casualties: Generator low water jacket temperature
Indications are a low coolant temperature alarm. Escalate and contact the Gen Team for support.
Additional inspections: Verify heater is functioning and coolant is flowing. If heater is off or coolant isn't flowing, verify breaker positions (power panel and customer panel) are closed. Verify heater contact is operating normally. Inspect all associated wiring for damage or indications of electrical fire. If there are signs of an electrical fire, open associated breakers to secure power.
Discuss the effects of High or low water flow on air handler operations
High water flow will cause moisture carryover from the evaporative media into the supply air- resulting in higher humidity and lower temperatures.
Low water flow will result in inadvertent media dryout- resulting in lower humidity and higher temperatures.
What are considered the 5 top responsibilities or priorities for an EOT in order?
1 - Alarms
2 - Rounds
3 - Racks
4 - PMs
5 - Projects
Describe the following as it pertains to the batteries: How many batteries does each UPS have
40 per string @ 12VDC each.
4-5 strings per UPS.
Explain how to fuel the generator including PPE and spill containment requirements
Generators are refueled through vendor contact and scheduling. DCEO are required to verify tank levels post fueling.
For sites with digital level indicators, read the indicator.
For sites without level indicators, the tanks must be dipped. Dipping tanks requires hearing protection, eye protection, and nitrile gloves.
What equipment does the House Uninterruptible Power Panel (HUPP) serve?
Controls: Gen CAM SWBD, UPS, USB, MV Switchgear, PDP, AMCOP, BACOP
Security loads: FACP, VESDA.
ERM: Air Handler Controls, BMS, EPMS.
POD: Air Handler Controls, BMS, EPMS.
Discuss the expected response for the following alarms: CRAHU mains power lost
General: Take HOA to Off. Check all fuses, wiring, and connections. Replace faulty components as necessary.
---
Check fuses FU8 and FU9 status and wiring. Check fuses FT6 and FT5-2 status and wiring. Check relay R2 wiring and connections as well as mains power and disconnect switch status and wiring. Check fuses FU6, FU7, and FT3 status and wiring as well as PW3 connection to controller input ID15. Replace faulty devices as necessary.
Describe how failed temperature cold aisle probes affect air handler controls operations.
A probe indicating too hot will result in greater cooling being applied (during winter, this may result in subcooling).
A probe indicating too cold may result in less cooling being applied and overheating the area.
Temp sensors that have failed or are out of range will not be used in any calculations by the controllers.
A temperature sensor is considered failed or out of range if it is below 20 or above 120°F.
Discuss the expected response for the following alarms: Cold aisle hotspots.
Escalate, Investigate condition of Mechanical equipment supplying air in that aisle.
Deploy fans or porta coolers as needed.
Verify hot aisle containment meets standard.
Verify temp sensor in working correctly.
Discuss the different classes of fire
Class "A" Fire: Wood, paper, traditional/organic combustibles
Class "B" Fire: Gasoline, petroleum, and synthetic combustibles
Class "C" Fire: Electrical, transformers
Class "D" Fire: Combustible metals (magnesium, zinc, etc.)
Class "K" Fire: Animal fats, cooking oil
Discuss how you would respond to a rack with elevated inlet temperatures.
Inspect temperature probe locations to determine if they have been relocated. Verify associated air handlers are operating properly. Deploy temporary cooling units where needed.
Define the following terms as it relates to the Generator: Run Mode
A manual mode of operation that forces the generator to start/generate power
Discuss the expected indications and response to the following casualties: USB main utility breaker failing to close when commanded
AMCOP will go into AUTOFAIL.
If generator is available, load is transferred back to generator. Verify loads (racks and mechanical) are operating normally. Reset AUTOFAIL.
If generator is unavailable, verify loads (racks and mechanical) transfer to alternate power supply.
For sites equipped with a USB catcher system, verify Deadbus timer is fulfilled and ATC transfers load to 480V Catcher.
Once load stability has been validated, escalate.
Explain how to verify that the Generator coolant heater and thermostat are operating correctly
On the Generator HMI an EOT will be able to see what the coolant temperature is. The coolant temperature should be above 90F (preferably above 100F).
Describe what work is permitted on blocked days? Where can we find that info? Where can we find the blocked day calendar? Why do we have blocked days?
Emergency repairs, rounds, rack installation, rack decommission, and visual audits.
Wiki. InfraOps Standfast Dashboard.
To ensure customer reliability during peak usage or inclement weather.
What situations should be escalated and what information is needed during an update?
Utility issues (Waveform Captures, Loss of Utility, Switchgear Issues) On gens or utility? Site stable?
UPS alarms (Unit Model and Serial Number will be needed) Load Stable? On inverter or bypass? Alarm still active?
Generator issues Is generator available to run if needed? Can USB be tied?
Communication (Loss of comms with Foreseer or BMS and associated devices) Cooling/power stable? What systems have lost communication? Increased rounds in progress? Loss of ICW Reason for loss? Tank levels? Cooling mode? Aisle temps? Racks status?
Purge event/cooling loss High room temperature? Pressure issues? Still in Purge? air handlers available? In manual or auto?
Any region-wide event
What are the time delays associated with Utility Power Returning?
6 minutes for the first lineup. 30 seconds for each additional lineup, sequentially.
What is an auto-fail and how can it be reset when the issue is corrected?
Autofail is an AMCOP condition defined by one of the following:
• Automatic operation has failed or fault has occurred
• Automatic transfer is interrupted
• Operator intervention is required to return the system to normal
After the cause is investigated and corrected:
•Turn the mode selector switch from AUTO to OFF/RESET
• Acknowledge the auto fail condition on the HMI
• Return the mode selector switch to AUTO
Discuss the policy for critical equipment maintenance.
Found here: https://w.amazon.com/bin/view/PDX_DCEO_Escalation#HPolicyforCriticalEquipmentMaintenance in addendum 13.
Lists the general policy for performing maintenance on critical equipment, the conditions that must be met in order to perform, and when to roll back. The listed evolutions include:
•Annual UPS/Gen maintenance
•Battery Maintenance
•IR Scans
•USB/ATS
•AHU/CRAHU
•Controls EPMS
•Inclement weather
What are the different automatic transfer times for the following transitions: Primary source stabilization
6 minutes for the first lineup. 30 seconds for each additional lineup, sequentially.
What is Cloudforge/Facility Inventory and Topology(FIT) and what is it used for?
CloudForge: Build is the consolidated home of Infrastructure data center capacity planning tools.
FIT owns, manages, and vends validated electrical (power) and mechanical (cooling) equipment inventory along with their topology (the connections between equipment) information for AWS owned or operated data centers, globally.
Both tools are used to inventory, manage and plan in regards to our equipment inventory.
What is the difference between hot, neutral, and ground?
Hot: Supply path for current.
Neutral: Return path for current.
Ground: Safety feature to eliminate shock hazards.
What is the purpose of a rack backfeed?
The purpose of a rack backfeed is to provide an alternative power path to the customer.
This is done so the normal path may be taken offline while still maintaining continuity of power to customer load.
Discuss Delta vs Wye connections.
Delta: 3 lines of equal voltage in a triangle configuration.
V*line* = V*phase*
I*line* = I*phase* x sqrt(3)
I*line* lags I*phase* by 30 degrees
Wye: 3 lines of equal voltage in a 'Y' configuration with a fourth, neutral line connected at the point where the 3 main lines merge.
V*line* = V*phase* x *sqrt*(3)
I*line* = I*phase*
V*line* leads V*phase* by 30 degrees
Define the following power redundancies: C2N
Twice what is necessary plus a catcher (zone defense).
Discuss the expected indications and response to the following casualties: USB main generator breaker tripping
AMCOP will go into AUTOFAIL.
If generator is not carrying load, escalate.
If generator is carrying load and utility is available, load is transferred to utility. Verify loads (racks and mechanical) are operating normally. Reset AUTOFAIL.
If generator is carrying load and utility is unavailable, verify loads (racks and mechanical) transfer to alternate power supply.
For sites equipped with a USB catcher system, verify Deadbus timer is fulfilled and ATC transfers load to 480V Catcher. Once load stability has been validated, escalate.
Explain how to manually run the generator without placing it on the utility bus
AMCOP > Login > Timers > Generator Exercise
AMCOP > Mode selector > Manual > Generator start > ON
Describe the operation of an ATS in the following situations including any transition times or time delays: Primary power is lost
Non-WMW: ATS will transfer to source 2.
WMW: Battery will supply load until drained, then load will transfer to source 2.
What is an IGBT and what is it for?
Insulated Gate Bipolar Transistor
Inverter in the UPS, used for converting DC to AC
Answer the following regarding rackdown events: Which racks will we lose if an IOB or PDP breaker trips? What will happen to EC2 and Networking Racks?
All Single Source (Prod) Racks will go offline.
N+C's will transfer to Catcher.
2N's will swing load onto their other source (A or B).
Explain what the difference is between arc flash PPE and electrical shock PPE?
Arc flash PPE is arc rated but is not rated for electrical shock protection (i.e. 40 cal suit)
Electrical shock protection is based on electrical insulation properties and is rated by the voltage level it protects against (i.e. Class 0 rated rubber gloves good up to 1000 volts).
Discuss the major steps of a UPS startup and shutdown
Shutting down a UPS:
Place UPS in internal bypass
Close MBP breaker
Open IOB breaker
Open MOBs
Open MIBs
Open BIBs
Open Battery breakers
Starting a UPS:
Close MIBs
Close BIBs
Start Rectifier
Start Inverter
Close Battery breakers
Close MOBs
Close IOB
Open MBP
Transfer load to Inverter
What are the AMCOP timer settings?
Utility Source Loss - 3 sec
Utility Source Stabilization - 9 min 30 sec
Out of Tolerance Event Delay - 55 sec
3 Strike Return Timer - 2 seconds
UPS on Battery - 50 sec
UPS on Battery Event Timer - 180 sec
Utility CB Failure to Open/Close - 3 sec
Dead Bus Timer - 90 sec
UPS Return to Utility Timer - 120 sec
Gen Source Loss Timer - 10 seconds
Gen Source Stabilization Timer - 5 sec
Gen Exercise Timer - 6 min
Gen Cooldown Timer - 5 minutes
Gen Crank Failure - 52 sec
Gen CB Failure to Open/Close - 3 sec
Open Transition Transfer - 2 sec
Whose permission is required to replace an ATS?
If it is a Sev2 scenario, then permission to replace an ATS is automatically granted in the event that not replacing the ATS will continue to impact customers.
Otherwise; on-call manager, CE, FM (or higher).
Explain how to manually operate the generator and utility breakers in the switchgear
AMCOP > Mode Selector > Manual > Generator start > ON > Verify voltage/Hz > AMCOP HMI > Transfer load to generator (Open Utility breaker/Close generator breaker) AMCOP > Mode selector > Manual > Generator start > ON > Verify voltage/Hz > Switchboard > Open MCBU > Close MCBG
Explain what the SPCC is and where can it be found?
Spill Prevention Control and Counter Measure
Site Specific. Policy.amazon.com
State the KW rating of the generators
KW rating will vary for site or PERDIX.
PDX4 standard is 2000Kw (2MW)
Discuss the reasons for long time, short time, instantaneous, and ground fault settings
Long: Overload Protection
Short: Delayed short-circuit Protection
Instantaneous: Instant short-circuit Protection
Ground Fault: Short-circuit to ground protection
What is Fast Loop Restoration Scheme (FLoRES)?
FLoRES is an automated protection system that automatically detects and isolates electrical faults within 5-10 cycles and restores voltage to the unaffected sections within seconds or less.
Explain how to use a psychrometric chart
A Psychrometric chart consists of the following:
X-axis: Dry Bulb temp
Y-axis: Humidity ratio, Dew point temp, vapor pressure
Upper limit: Saturation curve temperature
Diagonal axis: Enthalpy
The chart is read by taking any two known parameters, and identifying the point of intersection.
How does a variable frequency drive work?
A VFD converts incoming AC power to DC power via a rectifier. The DC power is then inverted back to AC power via IGBTs at a desired voltage and frequency that correlates to desired changes in speed of a motor. This allows precise controlling of motorized equipment.
Discuss the expected indications and response to the following casualties: Generator low oil pressure
Escalate to On-all Manager, call the FOC and get a TT cut, notify Gen team. Await permissions for actions or until qualified engineer/ tech arrives on site to assess.
What’s the difference between a positive displacement and centrifugal pump?
Positive displacement: At a given speed, pumps a volume regardless of downstream pressure.
Centrifugal Pump: At a variable speed and flow rate, will pump downstream if pressure doesn't exceed discharge pressure.
What is the difference between series and parallel pump operations?
Pumps in series will raise discharge pressure at a constant flow rate.
Pumps in parallel will raise flow rate at a constant discharge pressure.
Define the following power redundancies: 2N
Twice what is necessary.
Discuss normal operating parameters of a generator under load
Coolant temperature (<208 F)
oil pressure (>40 psi)
speed (1795-1805 RPM)
frequency (59-61 Hz)
amperage (0 A if unloaded)
voltage (475-485 V).
What is an AMCOP Auto Fail condition?
Autofail is an AMCOP condition defined by one of the following:
• Automatic operation has failed or fault has occurred
• Automatic transfer is interrupted
• Operator intervention is required to return the system to normal
Define an open and closed transition and list examples of each
Open Transition: Original power source breaker is opened before closing new power source breaker. This is done to prevent inadvertent backfeeding in addition to accidentally paralleling out of phase sources.. An example of this is MCBU/MCBG transitions.
Closed Transition: New power source breaker is closed before opening original power source breaker. This is done to ensure continuity of power. An example of this is MBP/IOB.
At what temperature do air handlers enter evaporative cooling mode?
Varies by site.
PDX4:
PODs - 81 degrees
ERMs - 72 degrees
Discuss the expected indications and response to the following casualties: Generator high engine temperature
Escalate to On-all Manager, call the FOC and get a TT cut, notify Gen team. Await permissions for actions or until qualified engineer/ tech arrives on site to assess.
What are the pump/fan affinity laws?
Pump laws describe the changes in flow rate, pump head, and power that result from a change in either the diameter of the pump impeller or impeller speed.
Where:
Q=Volumetric Flow Rate
dp=Head/Pressure
P=Power
n=impeller speed
d=impeller diameter
Q1/Q2=(n1/n2)(d1/d2)
dp1/dp2=(n1/n2)^2(d1/d2)^2(2)
P1/P2=(n1/n2)^3(d1/d2)^3(3)
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