cap tire in pipe

[Gerby]

I recently hooked up a sewage pump that was in a large holding tank. This tank came with a 6x6x4 pvc box inside the tank.The tank is in the floor and a 2" pvc pipe comes out of the j.b. into the factory motor control.What I did was run the cords for the pump the pills and pump sensors staight through the 6x6 into the control. However the inspector didnt like the cords run in the pipe ,so I had to make junctions in the 6x6 and run rw90 down from the controller to the jb.Now I have looked in section 4 and I couldnt find anywhere that I shouldnt ba able to do this. Does anybody have a rule for me.

[neil seidner]

Gerby: The rule you are looking for is 12-902. Which states that a conductor or cable in conduit must be listed in table 19 as being suitable for use in conduit. Cab-Tire is listed in table 11, not table 19.

[Navyguy]

Hi to all

In that case, would not the pipe be used soley for mechanical protection and be exempt from that rule. If the cab tire was the right type you would not even need the pipe...

What are your thoughts...

Navyguy

[Tony Moscioni]

In Ontario, we've issued a Bulletin where we deal with the cabtire issue in a PVC conduit in a wet well environment.


Alternate Electrical Requirements For Sewage Pumping Station Concrete Wet Walls

Rule 18-004



Issue



Sewage pumping station wet wells, which have been classified as Class 1, Zone 2 required threaded metal conduits within the wet well, with conduit seals close to the point of conduit entry, in order to comply with the electrical requirements of Section 18 of the Ontario Electrical Safety Code.



This practice has had a number of limitations, particularly in the corrosive atmosphere of a sewage wet well. Numerous complaints have been received about the condition of the electrical system in wet wells and it was considered ad?visable to find an alternative wiring method in this special application.



The Electrical Safety Authority has prepared electrical requirements, which are an alternative to the requirements of Section 18, detailing wiring methods which may be used in wet wells classified as Class 1 Zone 2 or Class 1 Division II as permitted by NFPA 820 Standard for Fire Protection in Wastewater Treatment and Collection Facilities 1999 edition.



Caution must be exercised in assuming a Class 1 Zone 2 classification. Recently, sewage wet wells have been classified as Class 1 Zone 1 locations. Before proceeding with a sewage pumping station, please ensure the appropriate authority has classified the wet well. See Bulletin 18-1-*.



The Electrical Safety Authority recommends where possible, where sewage wet wells are to be construct?ed and the classification is Class 1 Zone 2, the wiring methods in the wet well be to this alternate wiring method.



Direction



In a Class 1 Zone 1 location, Section 18 wiring methods shall be followed, which could include the use of intrinsically safe circuits and combustible gas detection instruments.



In a Class 1 Zone 2 location, the following minimum alternative electrical requirements shall be accepted.



Alternate Electrical Requirements



1. General



a) Sewage wet wells are associated with three forms of sewage pumping stations:

- With submersible pumps located in the wet well

- With factory built, dry pit, steel shell pumping stations

- With site built, dry pit, concrete shell pumping stations.

b) Conduits from the wet well shall terminate at a junction box, or boxes, located outdoors.

c) Conduits from the outdoor junction box or boxes, to the pump control panel or lighting panel shall be effectively sealed as per Rule 18-158.



2. Essential Equipment Only in the Wet Well



a) Provide only essential electrical equipment and devices in the well required to operate the pumping station because of the highly corrosive location. e.g., float level switches, submersible sewage pumps, wet well lighting.

b) EXCLUDE such items as junction boxes, fans, blowers, heaters, receptacles, disconnect boxes or switches.

c) Where wet well lighting is considered necessary, provide wall mounted fixtures, suitable for a Class I, Zone 2 location, coated with corrosion resistant epoxy paint, baked-on and with stainless steel guard holding screws. Locate the fixtures near the ladder or suitable access point for lamp replacement and secure to the wall with stainless steel or nylon screws. Use an aluminum close ****** and a rigid PVC female adapter to connect the lighting fixture box to the rigid PVC conduit. Coat the ****** with epoxy paint.

d) NOTE: It is recommended that electrical equipment for flow and/or level measurement (except float switches) be located outside the well. If this, or other equipment, is required inside the well, provide equipment specifically approved for the classification and use in sewage wet wells.

e) Locate the well ventilating fan, if required, out?doors, arranged to force outside air into the well.



3. Wiring Inside the Wet Well to Float Switches and Submersible Pumps



a) Wiring to float switches and submersible pumps shall be approved flexible cords, type SOW, SOOW, STOOW, or STOW.

b) Sufficient cable slack is provided to permit adjustment or removal of the equipment. Cable slack shall not exceed that required for normal operation or 3m maximum.

c) Arrange for a cable loop where the cables leave the elbow of the conduit.

d) Where cable is run around the walls, support it by nylon clip hangers every 1.0 m maximum, secured by stainless steel or nylon screws to the wall.

e) Terminate the conduits, carrying flexible cables, where they enter the well. Terminate horizontal conduits with an elbow pointing downwards.

NOTE: This places less stress on the cable.

f) DO NOT seal these conduits in the well. Allow them to breathe and drain.

g) DO NOT splice cables inside the well.



4. Conduit Runs Inside the Wet Well for Lighting, etc.



a) Provide runs to lighting fixtures and other fixed equipment in rigid PVC conduit with a green insulated copper bond wire sized as per Table 16.

b) Secure the conduit to the ceiling and/or walls with PVC clips and stainless steel or nylon screws.

c) DO NOT seal the conduits where they enter the well. Provide an open tee fitting at the conduit low point in the well to allow it to drain and breathe.

d) NOTE: Locate the switch for the well lighting in the outdoor control panel or inside a non-hazardous room. Use a circuit breaker with ground fault protection.



5. Conduit Runs from Junction Box to Wet Well



a) Run rigid PVC conduits from the bottom of the outdoor junction box to the wet well. Do not run these conduits through a non-hazardous room or area.

b) Slope the horizontal conduit runs so as to drain any moisture into the well.

c) After wiring, seal the end of the conduit at the junction box with a "Duxseal" mastic plug or equivalent.

d) Provide conduits large enough so that one flexible cable can be replaced without damaging other flexible cables in the same conduit.

e) Provide separate conduits with recommended minimum sizes for:

- Each submersible pump for power (and sensor), 1" minimum.

- Float cables, 1" minimum for 2 cables and 1 1/2" minimum for 3 cables.

- Lighting runs, etc., 3/4" minimum.



6. Junction Boxes



a) Provide a rigid PVC junction box, or boxes, outdoor weather proof type for all power, sensor and lighting conductors going to the wet well.

b) Ensure the box is adequately sized to permit splicing of the conductors under in-service conditions, without damaging the other conductors.

c) Locate the box outdoors with at least 1m clear?ance above grade and preferably not more than 10m from the wet well. Position the box to limit bends in the conduit runs to the wet well.

d) Splice all conductors inside the junction box with insulated compression connectors and then taped with approved insulation tapes or heat-shrinking tubing.

Number the conductors on each side of the splice with numbered tape markers.

e) The mastic plug in the PVC conduits entering the junction box are not effective seals as required by Section 18, therefore the interior of the junction box shall be Class 1 Zone 2.

f) The recommended locations of the junction boxes in the various types of pumping stations are shown in the attached figures and applied as follows:



Figure E1 - For a submersible pump station, where the pump control panel is located at the well and the electrical supply terminal pole is remote from the well, over 10 m.



Figure E2 - For a submersible pump station, where the pump control panel is located on the electrical supply terminal pole, which is remote from the well, over 10 m.



Figure E3 - For a submersible pump station, where the pump control panel is located on the electrical supply terminal pole which is close to the well, less than 10 m.



Figure E4 - For a submersible pump station, where the control panel is located in a building, e.g., an emergency power set building, which is less than 10 m from the well.



Figure E5 - For information - submersible pump station.



Figure E6 - For a factory built, dry pit, steel shell, underground pump station.



Figure E7 - For, a site built, dry pit, concrete shell pump station, where a building is located over the wet well and dry well, e.g., for an emergency power set.



7. Conduit Runs from Junction Box to Control Panel, etc.



a) Provide approved Class 1 Zone 2 conduit seal fittings, straight or angle type, at the junction box.



b) Run PVC conduit from the seal fitting to the control panel, etc.



c) After the building wires are installed, tested and the installation approved, install approved sealing compound in the seal fittings.



NOTE: Where the junction box and rigid PVC conduit, located outdoors, is subject to vandal?ism and/or mechanical vehicular damage, protect the conduit and box with a metal shield or guard.


Tony Moscioni
Electrical Inspector
Electrical Safety Authority