Every week we will be including additional questions and informal UPC and UMC interpretations
- Does a factory supplied switch or breaker that is mounted in or on mechanical equipment satisfy the requirement of Section 309.0 for a "positive means of disconnect adjacent to and in sight from the equipment served?"
- No. The requirement for a disconnect is intended to allow the equipment to be replaced without having to isolate the equipment from a remote location. Therefore a disconnect must be located adjacent to or mounted on the exterior of the equipment to allow the equipment to be isolated at the equipment location to make it easily replaceable.
- In reference to UPC Sections 218.0 and 710.9, would the pump for a sewage ejector in a duplex be considered public or private? This question is for the purpose of using a dual pump system.
- Section 218.0 defines a private system as one which serves a “family or an individual.” Therefore, any system of piping, fixtures, or a sump which serves two or more families is considered to be public use. Since Section 710.9 requires dual sewage pumps or ejectors for public use occupancies, dual pumps are required for a duplex. See also 218.0, Public or Private Use and Public or Public Use
- Does the height restriction of 8 feet in Section 304.2 (303.2, 2009) also apply to Section 701.2, which requires the volume of the room or space to be equal to or greater than 50 cubic feet per 1,000 Btu/h?
- No. This calculation is used only for calculating the minimum volume of rooms containing fuel-burning equipment not listed for closet or alcove installation. Note: The reference to the 8 foot ceiling in the training manual is only a coincidental example, as most ceilings are approximately 8 feet in height.
- Is it permissible to size sprinkler supply piping based solely upon the demand load of the largest individual sprinkler zone(s)?
- Determining the fixture unit demand based on the greater number of sprinkler heads within multiple zones is a viable alternative. This would require the approval of the Authority Having Jurisdiction based on the provisions found in Section 301.2. (2003/2006/2009/2012) 301.3 (2015) Also see Appendix A, Table A-2 (2003/2006/2009) Table A 2.1 (2012) Table A 103.1 (2015)
- In the UMC regarding a room containing the refrigerant compressors for a large grocery store: 1. When the refrigerant quantities in a single system exceed the amounts in Table 11-1 for a single system, which would otherwise require a refrigeration machinery room, can the room be designed so that it is open to either the main floor or other areas that are large enough to meet the allowable quantities as shown in Table 11-1 to eliminate the need for the refrigeration machinery room? 2. Does footnote 7 of Table 11-1 indicate that this table, pounds per 1000 cubic feet of occupied space, is not applicable for determining when a refrigeration machinery room is necessary?
- 1. Anytime the amount of refrigerant in a system exceeds the allowable amount in Table 11-1, a machinery room is required. Additionally, if an A1 system having an aggregate combined compressor horsepower of 100 (73.55 kW) or more, a machinery room is required. Since the table is based on cubic volume of space, all areas that freely communicate with the space could be used to calculate the volume. The concern would be the size and location of the communicating opening which would have to be determined and approved by the AHJ. 2. No. Footnote 7 clarifies that refrigeration machinery rooms and cooling systems used for human comfort are not subject to being sized based on pounds of refrigerant per cubic foot of space.
- Does UPC require all bathtubs to be equipped with an overflow? If so, what section?
- The Standards for fixtures listed in Table 1401.1 (2009/2012), Table 1701.1 (2015) all indicate that overflows are required on bathtubs and whirlpool bathtubs. These same Standards indicate that the overflow requirements are optional for sinks, lavatories and bidets. If an overflow is provided with a fixture, section 403.0 (2009); 404.0 (2012/2015) shall be followed for proper installation. Section 409.3 is referring the installer to section 403.0 (2009); 404.0 (2012/2015) to guide the installer on how to pipe the overflow that is provided on a Bathtub or whirlpool bathtub.
- According to the UMC venting tables, the NR designation means "not recommended." Does "not recommended" mean the same as do not install venting this way?
- The NR designation is similar to the NA designation in the UMC. It indicates a configuration that is not permitted. The solution is usually substituting a double-wall connector for a single-wall. The lengths of single-wall connectors that may be used are limited due to the heat loss of this vent material. The vent gas heat loss causes excessive condensation in the vent and eventual failure.
1. Is a future gas “stub-out” required to be provided with a shutoff valve and cap? 2. Is a capped outlet without a shutoff valve considered a completed gas system?
1. No. The minimum requirement is a cap. 2. Yes.
- Is Teflon tape an approved pipe joint material for gas pipe installations?
- Yes, listed Teflon tape is acceptable when carefully and correctly applied to male threads only, since it is insoluble in the presence of fuel gas.
- In the UPC, 1. Would a 4' long drain tail piece require support for vertical piping? 2. Would the no-hub coupling installed at the floor drain on the top of the pipe provide support to the piping? 3. Would the no-hub coupling installed at the base of the pipe at the 90 degree fitting provide support?
- 1) No. A fixture tail piece is limited to 24 inches. If the fitting that connects the tail piece to the fixture is properly supported the tail piece would not need further support. 2) No. You should not rely on no-hub couplings to support the weight. 3) No. No-hub couplings are designed as a means to provide a water tight joint, not to support pipe. The 90 degree fitting must be properly supported.
- The UMC appears silent on the length of the guardrail. How long should the guardrail be? I propose it should extend at least 6 feet from any part of the rooftop equipment. What guidance can you give concerning the length of the guardrail?
- Although the code is silent on the length of the rail, it would seem reasonable that the guardrail extend the entire length of the equipment as a minimum; although, extending it further would provide additional protection. The Authority Having Jurisdiction should have the final decision on what would be acceptable.
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