Monday, August 31, 2020

The Mysterious Oily Green Residue On Electrical Equipment

The Mysterious Oily Green Residue On Electrical Equipment




This may be an old topic for seasoned home inspectors, however I feel it is worth taking another look at this issue. I first noticed this several years ago, and am not to proud to admit that I thought it was dielectric grease. After further research I discovered that this is actually the breakdown of a “plasticizer” used for the wire insulation. They added this to make the wire more flexible. Elevated temperature and possibly humidity can cause the plasticizer compound to separate from the insulation on the wire. The plasticizer can then travel along the wire and be visible on the exposed part of the wire or on a device like a circuit breaker or receptacle. Common wire insulation has an outer nylon jacket. The plasticizer cannot penetrate this jacket, therefore it runs down the wire strands or conductors. This is why it is most noticeable where the wire conductors are exposed or at a termination. The effects of this process cause the wires to become less flexible and more brittle. Residue on devices may also cause connection issues and possibly failure. What should a home inspector be looking for and how to advise your client:

 

  • Green oily residue – this should not be confused with dielectric corrosion
  • The surfaces should not be cleaned
  • This may be confused with lubricant use to pull wires.
  • The oily residue is normally found on the ends of the wires or where the conductors are connected to a device, NOT on the outside where a lubricant may have been applied in order to pull wires through conduit
  • If this residue is observed, the electrical equipment and devices are probably damaged. The residue may have entered the inside of the components
  • The “plasticizer” is a petroleum based product and may cause deterioration to insulation used in some electrical devices
  • Recommend your client seek the services of a qualified electrician to evaluate and replace any areas where this has taken place

Monday, July 27, 2020

Cantilevered Areas


Cantilevered Areas






Cantilevered areas and “allowable spans” are always of concern to home inspectors. For a couple reasons: 1 – many times we are unable to view the structure where these cantilevered areas are. 2 – There seems to be confusion on the requirements for cantilevered areas.
The distance your joists can safely cantilever or overhang is determined by the size of the joists, the wood type and grade of the lumber and the spacing between joists. Many building departments limit joist cantilevers to 24" maximum. Cantilevered areas are also prone to damage at the area where they exit the structure. The American Wood Council states that cantilevers are limited to 1/4 the span of the joists, (refer to the chart above). Specifically the joist must back space at least 3 times the distance of the cantilever if the cantilevered area is supporting a wall or roof. The member should back space at lease 2 times the distance of the cantilevered area if not supporting a wall or roof structure. What should a home inspector be looking for;

  • A general home inspector rule of thumb in the field; cantilevered distance should be no more than 2 times the width of the joist. For example a 2x10 joist actually  measures 9 ½”. Therefore the cantilevered distance should be no more than 19 inches.
  • Examine both areas inside and outside of the house for damage or deflection
  • Joists or members should be installed “crown up”
  • Maximum allowable overhang cannot exceed 1/4 of the actual main span.
  • Evidence of leaks  / moisture at the house insertion, inside and outside
  • Proper flashing and counter flashing should be visible
  • An adequate drainage plane ensuring water is drained away from the structure
  • If possible, check the basement structure to ensure the cantilevered section is properly installed
  • A minimum of 5 framing nails should be used to attach the joists to the rim joist

Monday, June 29, 2020

Sewage Ejector Inspection

                                                Sewage Ejector Inspection


         




Sometimes called “lift pumps” sewage ejectors could be installed for a whole house or just a one or more fixtures. Sometimes servicing a basement or below grade bathroom or utility room. Sewage ejectors are necessary when the fixtures are below the main sewer or septic system. Sewage ejectors use a grinder pump located in a crock or sump. The pump is activated by a float switch.  Some sewage ejectors are just for waste water and do not have a grinder pump. They are usually located at a utility or slop sink.

The sewage ejector should have a sealed lid on it and be accessible. The discharge pipe should be at least 2 inches in diameter. The vent pipe should be at least 1 ½ inch, however many municipalities recommend a 2 inch pipe is used. Air admittance valves are not approved. Although during a visual home inspection, an inspector is limited to turning on the water and listening to ensure the sewage ejector system responds and does not leak, there are other things a home inspector should be looking for like:


  • The discharge pipe should connect to the top of the horizontal main DWV using a wye connection sweeping the proper orientation
  • There should be a back flow or check valve in the horizontal position or at a 45 degree angle with the valve pivot on top
  • The ejector should be plugged into a GFCI protected outlet
  • For units that are direct wired; the circuit should be GFCI protected
  • The crock should be 18 inches in diameter and 24 inches deep
  • The cover should be sealed 
  • A minimum of a 2 inch gate valve should be installed in close proximity below the main DVW and after the check valve
  • The system should be vented to the atmosphere

Saturday, May 30, 2020

Misunderstood Electrical “Defects”




                                                                      
                                          


I hear home inspectors and even “licensed” electricians disagree on what an electrical defect is. A defect or “code violation” is often misunderstood and confused. I hear inspectors say things that are unsubstantiated and look over items that are clearly an issue. As home inspectors, we are not conducting an electrical code inspection, however many of the items home inspectors are inspecting and reporting on are in fact, code related. One of the things that stand out is sloppy work. Although there is nothing specific, some of the guidelines for electric work are: Wires should run in straight lines that are level and plumb, NM wire should not be twisted so it lays flat, electrical equipment should be installed level and plumb and performed in a workmanship like manner. Here is some clarification on common defects that may be overlooked:

·         Wire should be secured within 12 inches of a service panel and 4 1/2’ throughout the run
·         Outdoor circuits should not be connected to a kitchen appliance circuit
·         Lateral service riser should be secured within 3 feet of the meter
·         Non-Metallic wire going through a metal conduit must use a proper bushing / wire / cable clamp connector
·         GFCI’s are required for all receptacles in a garage except; receptacles that are not readily accessible (requiring a ladder), and receptacles that supply a dedicated single appliance.
·         Electrical equipment that is not Underwriters Laboratory (UL) listed should not be used
·         UL listed ground clamps are made of brass, not aluminum
·         Unapproved circuit breakers. If the breakers are not the same manufacture as the panel or a direct manufacture replacement, that is a defect, even if they fit
·         All junction boxes should have covers
·         Outlets should not have paint on them

Monday, March 30, 2020

Is PVC Safe To Use For Venting Appliances?


Is PVC Safe To Use For Venting Appliances?

Many of the direct vent high efficiency appliances are vented using PVC. Specifically Schedule 40 PVC. Many inspectors and installers are starting to notice discoloration on these pipes. Some appliance manufacturers do not recommend venting their appliances in specific types of PVC pipe. Some manufacturers supply and recommend using their vent kits. Often times these are metal vents. Some of the PVC pipe manufacturers have indicated that their pipe was not produced for this application. Here is a warning from Charlotte Pipe on their website:

Combustion Gas Venting
Failure to properly vent combustion gas may result in serious injury or death from carbon monoxide.
• Always install / use pipe or fittings as specified by the
appliance manufacturer's installation instructions to
vent appliances.
• Never use PVC cellular core, ABS cellular core pipe or
ConnecTite® fittings for combustion gas venting.

Almost all appliance manufacturers agree that cellular core PVC, cellular core CPVC, and ABS should never be used to vent any appliance, only solid core. The difference between the two is that the inside and outside walls are solid PVC (solid core). Cellular core pipe has an inner core that is cellular (or foamed) PVC, a material that includes tiny bubbles of entrained air. For pipe manufacturers, the main advantage of cellular-core PVC is lower cost, since it requires less resin to make than solid core pipe. Cellular core will also break down with high temperatures faster. When PVC pipe degrades from heat it may produce toxins. Here is a link to a great video from TOH: https://youtu.be/ylX2gfggu_o
 So what should a home inspector be looking for:

·         The Plastic vent pipe should be stamped “Gas Vent Type”
·         Ipex manufactures an approved CPVC flue gas venting pipe that is rated for 90 C (194 F).
·         The plastic vent pipe should not be discolored
·         Discolored pipe may also be leaking flue gases at connections
·         Many approved plastic vent pipes are actually solid core CPVC which is rated for 90 C or 194 F.
·         Schedule 40 PVC is only rated for 60 C or 140F
·         Check the pipe; it will be stamped “Cellular Core”
·         Solid core may be marked as such or as “Pressure Pipe”
·         The PVC pipe and fittings should be from the same manufacturer
·         When in doubt, check with the appliance and pipe manufacturer


Saturday, February 29, 2020

Inspecting Hydro-Air Heating Systems


Inspecting Hydro-Air Heating Systems


Hydro-Air Boiler System


 Heat Pump Geo-Thermal System

A hydro-air system employs hot water coils in an air handling system. Basically, it is a forced air system with coils (Hydronic Coil) heated by hot water running through them. The hot water in the coil is supplied by a hydronic boiler. Some geo-thermal systems employ hydro-air if forced hot air distribution is desired. It could also be integrated in one air handler using the same coils for an air conditioning system. This is basically a heat pump employing a compressor. This configuration uses refrigerant. If supplied by a boiler; these units are very efficient in the winter months. The inspection on hydro-air units are different than a conventional forced hot air furnace. What should a home inspector be looking for:


·         There may be a timed delay when the thermostat calls for heat to allow the coils to heat up. The timed delay will be shorter on a heat pump system.
·         The unit will either have a dedicated zone valve, circulator, or pump / check valve installed in the air handler (see diagram above). This must activate properly for the system to respond.
·         Keep in mind that the hydronic supply from the boiler will most likely be used for domestic hot water and should be separated from the coils used for the Hydro-Air system.
·         A mixing or tempering valve (can be seen in detail above) should be installed if the unit is also producing domestic hot water. The water for the heating coils will be considerably hotter than the domestic hot water should be. The mixing valve will ensure the temperature is lowered to an acceptable level.
·         If possible the air handler should be positioned below the water heating source to prevent thermosiphoning; (mixing of hot and cooled water), if a circulator or pump is not employed.
·         The heat pump should be inspected as normal.
·         The duct system should be well insulated.
·         If integrated with the air conditioning system (heat pump), a condensate discharge should be present.
·         Obviously there is no flue pipe or carbon monoxide issue to be concerned with at the air handler.
·         The boiler or heat pump supplying the unit should also be inspected at this time.

Wednesday, January 29, 2020

Requirements For Surge Protection



 



The 2020 NEC updates require surge protection for most electric applications. Installing surge protection is something that many home inspectors already recommend. We will look at the different types and the proper installation of surge protectors. A “surge” is a very brief surge of voltage on the electrical lines. A surge can be caused by work the utility company may be performing, power outages, turning a breaker on and off, devices / appliances with large power draws, and a lightning strike.
A surge can cause damage to many sensitive electrical devices and appliances that have a motor. There are 4 types of surge protection devices. Type 1 is installed at the line side of the main electric service panel between the utility pole / transformer and where the electric conductors enters your service panel. Type 1 protect against external power surges, but do not offer protection against internally surges. You would see this device at the meter. Type 2 surge protectors are installed on the load side of the main service panel and will protect against external and internal power surges. This unit can be directly connected to the main service panel. It will look like a double pole breaker with no handle. A neutral stranded conductor from the surge protector will be connected to the neutral bus. Green conductor would go to the ground bus. This is for installation in a main service panel and is normally closest to the main service disconnect or the main service lug.  An external surge protection device is installed either next to or directly on the outside of the main service panel. Two black / hot conductors will be connected to a double pole circuit breaker closest to the main service disconnect or the main service lug. The size of the breaker is determined by the manufacture. I see many that are rated for 20 amps. This can easily be looked up to ensure it is properly installed. A white or neutral conductor is connected to the neutral bus, green to the ground. Type 3 surge protection devices are located at the devices. Surge protective receptacles can be installed in place of a typical receptacle. The wiring is the same. Surge power strips can also be used for protection. They should not be confused with a power strip that does not contain surge protection. Type 4 surge protectors are surge protection modules for industrial applications. They can also be directly wired in. In addition, they will protect industrial devices that use servo motors and automation drives.