Postal Exam 955 (USPS Maintenance Mechanic) Practice Tests
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What Is the Postal Exam 955?

The Postal Exam 955, also known as the USPS Maintenance Test, is used to screen candidates applying to various USPS maintenance positions, such as Maintenance Mechanic, Electronic Technician, Building Equipment Mechanic, and more. The Exam is 75-minute long and covers 8 content areas.

The test is based in content and structure on the Ramsay Test known as the MultiCraft test.

What Is the Passing Score for the 955 Exam?

The minimum passing score for each of the Postal Exam 955 content areas is 70. If you fail to reach this score, you’ll receive an “Ineligible” status. A retest is usually possible only 6 months after your initial test date.

How Hard Is the USPS 955 Exam?

The USPS 955 is a hard exam, as it requires solid theoretical and practical knowledge in a wide range of mechanical and electrical topics. Candidates with no experience in these fields will find the test harder. That being said, prior prep can help increase your chances of scoring high.

What Are the Sections of the USPS 955 Exam?

There are five basic parts to the 955 Exam:

  • Maintenance Mechanic
  • Maintenance Mechanic MPE
  • Electronics Technician
  • Building Equipment
  • Spatial Reasoning

The first three parts correlate directly to scores for the jobs of the same title.

Building Equipment correlates to both Building Equipment Mechanic (BEM9) and Area Maintenance Technician (AMT9) jobs.

The spatial reasoning portion of the test is a general topic that’s likely to apply to all test scores.

The five basic parts are divided into 8 content areas:

  • AC/DC Theory, Power Distribution, and Electrical Maintenance
  • Motors, Control Circuits, Schematics and Print Reading
  • Digital Electronics, Power Supplies, Computers, PLC, and Test Instruments
  • Hydraulics and Pneumatics
  • Pumps, Piping, and Combustion
  • Power Transmission, Lubrication, Mechanical Maintenance and Shop Machines, Tools and Equipment
  • Welding and Rigging
  • Spatial Relations and Spatial Reasoning - Matching Figures and Visualization

Postal Exam 955 Sample Questions (Taken From the Complete Practice Pack)

AC/DC Theory Sample Question

This is a predominantly theoretical section that revolves around the fundamentals of electricity. While simple for many candidates, those who have not dealt with electrical theory recently will often find this section problematic and will need a focused recap to ace it.

In a 110V electrical system, there are three appliances: appliance A (550W) appliance B (770W), and appliance C (330W). Given that all appliances operate simultaneously, what is the minimum required fuse rating?

A. 30A
B. 25A
C. 20A
D. 15A
Correct Answer
Incorrect Answer

The correct answer is C.

The minimal fuse rating should be higher than the normal operating current of the system. Since an electrical system is connected in parallel, the total current in the system when all three appliances are working is the sum of all three.

The current consumption of each appliance is calculated by:

I = P/V


  • I = Current [Ampere]
  • P = Power [Watt]
  • V = Voltage [Volt]


  • Appliance A consumes 550/110 = 5A
  • Appliance B consumes 770/110 = 7A
  • Appliance C consumes 330/110 = 3A

The total current in the system is 5 + 7 + 3 = 15A

In order to withstand normal working conditions, the minimal fuse amperage rating must be greater than 15A, thus 20A.

Motors Sample Question

This is a relatively practical section, but theoretical knowledge of motor types and functionality is required as well.

In induction motors, the difference between the synchronous and asynchronous speed of the rotor is referred to as:


A. Single phasing
B. Slip
C. No-load speed
D. None of the above
Correct Answer
Incorrect Answer

The correct answer is B.

Induction motors which are also called asynchronous motors work on the principle of induction which is inducing a current in the rotor by changing the magnetic field of the stator.

We can differentiate two definitions of speed in induction motors:

  • Synchronous speed – The speed of the changing magnetic field.
  • Asynchronous speed – The speed of the rotor (which is different from the synchronous speed).

The difference between these two is called slip. Therefore, B is the correct choice.

As for the other answers, single phasing (A) occurs when one of the motor terminals is loose or disconnected making the motor run on a single-phase. No-load speed of a motor (C) is the maximum speed of a motor when there is no load applied.

Control Circuits Sample Question

With the advancement of technology, this section becomes increasingly important in the 955 test. It covers all levels of control circuits, from fundamental concepts to the advanced analysis of ladder diagrams.

Identify the relay type shown below:

Postal Exam 955 Sample Question Electrical Theory


D. None of the Above 
Correct Answer
Incorrect Answer

The correct answer is B.

SPDT is a single pole double throw relay. The schematic diagram of an SPDT is shown below.

There are three terminals:

  • COM (common)
  • NO (normally open)
  • NC (normally closed).

When the relay is OFF, the COM terminal is connected with the NC terminal and when the relay is ON, the COM terminal is connected with the NO terminal. The schematic diagram of SPST (single pole single throw) and DPDT (double pole double throw) are also shown below.

USPS Exam 955 electrical sample question answer

PLC Sample Question

What is the equivalent Boolean expression for the PLC program below?

USPS Exam 955 Sample Question PLC


Correct Answer
Incorrect Answer

The correct answer is A.

Below are the steps of analysis:

USPS Exam 955 Sample Question PLC Answer

Test Instruments Sample Question

This section deals with electrical test instruments such as ammeters, meggers, and multimeters. While most candidates are familiar with the basic operation of these tools, the Postal Exam 955 test questions tend to be a bit more in-depth.

In electrical circuits, voltmeter is always connected in ____________ and ammeter is always connected in ____________.


A. series, parallel
B. series, series
C. parallel, parallel
D. parallel, series
Correct Answer
Incorrect Answer

The correct answer is D.

In electrical circuits, voltmeters are always used in parallel to the nodes where the potential is required to be determined. However, ammeters are always connected in series to measure the desired current in the branches. These connections are shown in the figure below.

USPS 955 test instruments answer

Hydraulics and Pneumatics Sample Question

Hydraulics and pneumatics are two of the most prevalent topics in this test aimed for strictly mechanical positions. Apart from being familiar with practical methods and concepts, this section also deals a lot with theoretical knowledge. This makes this section a pain point for experienced candidates in particular.

Which type of valve should be used when a precise, low flow is required?

A. Check
B. Needle
C. Gate
D. Both A and B
Correct Answer
Incorrect Answer

The correct answer is B.

A needle valve is constructed as an elongated, narrow plunger inside a small port. This structure enables the valve to regulate the flow with high precision. However, it is not capable of withstanding high pressure.

A check valve is a valve that enables flow in only one direction, using a ball, a piston, or a spring-loaded flapper.

A gate valve operates by lifting a gate from the path of the fluid. These gates are planar and are mostly used with high-volume, unrestricted flow.

Piping Sample Question

Which type of pipe would be most recommended to install deep beneath the ground?

A. Schedule 20
B. Schedule 40
C. Schedule 80
D. Schedule 120
Correct Answer
Incorrect Answer

The correct answer is D.

The schedule of a pipe is a dimensionless number that refers to the wall thickness of a pipe. The higher the schedule; the thicker the wall.

When installing a pipe underground, it is important for it to have a thick wall due to the pressure of the soil and other structural elements that may lie on top of it. Therefore, a schedule 120 type pipe will be best suited for such an application.

Power Transmission Sample Question

This is another very prevalent mechanical topic. Although covering around 14 sub-topics (e.g. couplings, bearings, shafts, etc.), several sub-topics often constitute the majority of questions in this section, so they are more worthy of your attention.

What is the aim of flexible couplings?

A. Reduce load from the motor
B. Allow shaft misalignment
C. Installation at various machinery parts
D. Amplify torque
Correct Answer
Incorrect Answer

The correct answer is B.

The aim of flexible couplings (such as universal joints or Oldham couplings) is to allow a certain degree of misalignment between connected shafts (it may be an axial, lateral, or angular misalignment). Rigid couplings, on the other hand, require absolute alignment between shafts and are somewhat limited in that manner.

Spatial Visualization Sample Question

This part tests your ability to imagine what three-dimensional objects will look like after they have been rotated.

Two separate objects are placed at the center of the screen, each with a dot placed in one corner. The answer choices contain the same two objects, rotated in some way. Only one of the five options shows both the dots placed in the same corners as in the model.

Postal Exam 955 Spatial Reasoning Sample Question


1. A
2. B
3. C
4. D
5. E
Correct Answer
Incorrect Answer

The correct answer is C.


What Is the Next Step After Passing the 955 Test?

After you successfully pass the 955 Exam, there are two other crucial steps to the United States Postal Service hiring process.

Panel Interview (Oral Test)

You will be interviewed by two members of USPS maintenance management, and one member of USPS human resources.
They will ask you 5 questions for each job title. Some questions will be technical in nature and some questions will be related to work ethic and interpersonal relations.

Most importantly, they ask you safety questions. You should always remember that safety comes first and you need to be familiar with LOCKOUT/TAGOUT safety procedures.

Here are a few examples of questions you’ll likely encounter during this interview:

  • Explain how you would troubleshoot a fuse when the fuse is in the circuit, out of the circuit, and across three phases.
  • Explain the function and usage of an oscilloscope.
  • Explain the different usages of heatsinks in electronics in regard to both computing and its use in soldering.
  • Explain how you would go about troubleshooting a networking fault.
  • Explain Ohm's Law.

Drug Screening Clearance

To get hired, you must pass a 5-panel urine drug test. The USPS is strict about this issue and will turn down many qualified applicants because of the drug test, making it their biggest hurdle in finding employees.


About the Author:


Arbel is JobTestPrep's USPS exam specialist. He has over 15 years' experience working as a psychometric test instructor and has led JobTestPrep's efforts to provide thousands of USPS test-takers with the most accurate online prep possible since 2017. You can contact him at

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