PCU Installation, Operation & Maintenance Manual

What the PCU is

A UL Listed, fully welded 18-gauge stainless-steel enclosure that installs in the grease duct between the kitchen hood and the exhaust fan. Channels hold three rows of filters that remove particulate matter and grease vapor from kitchen exhaust. Removable doors give access to the filters and fire-protection components; a controls enclosure at the outlet end monitors system static pressure and drives a wall-mounted status panel.

Every model is 63 in. long; the number is the width in inches. Airflow values are for planning.

Filter sizes are nominal, in inches. Units can be stacked to save floor space; contact Molitron.

Filter rows, inlet to outlet

1. F1
   MERV 9 multi-pocket pre-filter (orange)23.31 × 23.31 × 12 in. (H × W × D)
2. F2
   MERV 14 multi-pocket high-efficiency filter (green)23.31 × 23.31 × 12 in. (H × W × D)
3. F3
   MERV 14 multi-pocket high-efficiency filter (green), or optional carbon filter23.31 × 23.31 × 12 in.; carbon 23.375 × 23.375 × 12 in. (H × W × D)

Half-size pre-filters and high-efficiency filters (24 × 12 nominal) are 23.31 × 11.31 × 12 in. (H × W × D). The filters sit in 1-in.-wide welded T304 channels (top, bottom and back side), sealed to the outer skin with high-temperature silicone.

Location

In the grease duct between the kitchen hood and the exhaust fan, indoors or outdoors, in an accessible location.

Direction

Inlet end from the kitchen, outlet end toward the exhaust fan.

Duct connections

Welded to the exhaust duct at each end, using the 1.5-in. perimeter flange.

Inlet duct

Provide straight duct on the inlet side of at least 3 times the duct diameter, to avoid system effect.

Exhaust fan

UL Listed for kitchen exhaust, backward-inclined utility type, with easily adjustable RPM. The PCU’s initial (clean-filter) resistance is 1.54 in. w.g.; size the fan for 2.5 in. w.g. plus hood and duct static losses.

Rooftop support

The two 4-in. stainless bottom channels support the unit across its full width. The installing contractor provides a code-approved roof curb.

Indoor suspension

Suspend the unit from its four hanger angles on spring hangers, with separate upper and lower threaded rods; the hangers, rods and hardware are by others. The project’s designer or installer selects the rod size, the hangers’ rated load and the anchorage. The removable eyebolts are for lifting and positioning only, not for hanging the unit.

Service side

At least 30 in. of free space between the access doors and any adjacent wall.

Other sides

At least 18 in. to combustible materials and building insulation, or zero clearance to noncombustible materials.

Above a ceiling

A permanent platform (by others) is required for servicing every four weeks, at the same height as the bottom of the unit.

Drains

Connect the three 1-1/2 in. cleaning drains to a common 2-1/2 in. drain and route it to the grease interceptor (by others).

Codes

Install and use only in accordance with these instructions. The installing contractor is responsible for local code requirements.

Molitron provides fire-suppression pre-piping: the PCU comes piped to its fire-suppression nozzles, ready for the fire-protection installer to connect. ANSUL is one brand option, and other customer-selected brands are supported.

The PCU does not connect to the building sprinkler system.

Fire-suppression design and approval are project-specific. Confirm the pre-piping on the project’s submittal drawing.

Field responsibilities

The fire-protection installer is responsible for the final hook-up, permits, drawing submittals and final testing, and provides the tanks, agent, piping from the tanks to the pre-piped nozzles, regulated actuators, cartridges and related components.

Detection

The detectors are mechanical fusible links, not electric.

Set high static pressure switch E after system start-up and after air balance is complete. Molitron provides the tools: one 24 VAC panel test lamp and one Allen wrench. Letters and terminal numbers are those of section 06.

Test lamp lit

The lamp lights. Keep it where you can see it and gauge B together.

1. 1Connect the test lamp
2. 2Find the clean-filter reading
3. 3Add 1.5 turns
4. 4Simulate weeks of cooking

Step 1 of 4

Connect the test lamp

After start-up and air balance, loosen the top of terminal 3 on block C and disconnect the red field wire. Connect one lead of the 24 VAC test lamp to the top of terminal 3 and the other to the top of terminal 1 (Common), beside the white field wire, and tighten both. The lamp lights. Leave it where you can see it and gauge B together.

BackNext step

1. Connect the test lamp. After start-up and air balance, loosen the top of terminal 3 on block C and disconnect the red field wire. Connect one lead of the 24 VAC test lamp to the top of terminal 3 and the other to the top of terminal 1 (Common), beside the white field wire, and tighten both. The lamp lights. Leave it where you can see it and gauge B together.
2. Find the clean-filter reading. Insert the Allen wrench through hole A into the brass port on the front of high static switch E. Turn it slowly clockwise until the lamp goes out. Note the reading on gauge B: the static pressure with clean filters. Write it in the record for this unit.
3. Add 1.5 turns. Turn the wrench a further 1.5 turns clockwise. The lamp stays out. Remove the test lamp, reconnect the red field wire to the top of terminal 3 and tighten it, then put the lamp and the wrench back on the shipping terminal.
4. Simulate weeks of cooking. In service, the green light shows the fan is on. As cooking loads the filters, static pressure on gauge B rises; when it reaches switch E’s setting, the red light blinks beside the green. Inspect the filters then, and replace those that need it. The time-lapse is an illustration: how quickly filters load depends on the kitchen.

1. 1Open the doors
2. 2Remove used filters
3. 3Check the gaskets
4. 4Install in order
5. 5Push each one home
6. 6Close up tight

Step 1 of 6

Open the doors

Remove the access doors on the service side.

BackNext step

1. Open the doors. Remove the access doors on the service side.
2. Remove used filters. Slide out the filters that are loaded with grease and restricting airflow. Steam-clean the interior if grease has built up.
3. Check the gaskets. Each filter takes a 1/4-in. closed-cell neoprene gasket on one vertical side. Green high-efficiency filters come with it fitted; add it to orange pre-filters and to any carbon filter without one. Only one gasket goes between filters: never add a second.
4. Install in order. From the inlet: orange pre-filters (MERV 9) in the first row, green high-efficiency filters (MERV 14) in the second, and green high-efficiency filters (MERV 14) or optional carbon filters in the third.
5. Push each one home. Push each filter individually into the upper and lower channels, gasketed side first, toward the wall opposite the doors: the first filter’s gasket seals against that wall, and each filter after it seals against the bare side of the one before, one shared seal per joint.
6. Close up tight. The last filter’s door-side vertical edge is exposed: add gasket there as needed so the row is tight when the door closes. The damper shields seal the top and bottom of each row. Then seat the doors against their gaskets.

Replacement filters

The owner or the owner’s representative replaces used filters as often as required. Use new filters of the same quality and manufacturer as the original equipment. Molitron accepts no responsibility for visible contaminants escaping the PCU if replacement filters do not match the original specifications or are not installed as described here. Order replacement filters from Molitron: 303-969-8888 · cleanair@molitron.com.

Cleaning

Steam-clean the inside of the PCU to remove any grease buildup.

The PCU and its component parts, the static pressure controls enclosure and the status panel, are warranted to be free from defects in material and workmanship for 12 months from the date of shipment.

What’s covered

A part that proves defective within 12 months is, after examination by the factory, repaired or replaced at no charge for parts. Labor, including installing the replacement part, is not included. Molitron does not accept returns of Molitron products.

Not covered

Parts damaged by the freight carrier between the factory and the destination, or by the installing contractor. The factory is not liable for incidental or consequential losses attributable to malfunctioning equipment.

The warranty does not apply if

• The PCU is not installed by a qualified installer per the factory instructions.
• The PCU is not installed to federal, state and local codes.
• The PCU is misused or neglected.
• The PCU is operated outside its published capacity.
• The invoice is not paid within the terms of the sales agreement.

The warranty is activated once the owner’s acknowledgement (section 10) is signed and returned to the factory. Email a signed copy to cleanair@molitron.com.

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Copy-ready text for a project specification, written from this manual. Edit the model for your project.

PCU — Kitchen exhaust pollution control unit

1. Manufacturer: Molitron Company Inc. Pollution Control Unit (PCU), Model EPFA-[24|36|48|60|72|84|96|108|120|132|144].
2. Listing: UL Listed under File MH45752, investigated to UL 8782, Outline of Investigation for Pollution Control Units for Commercial Cooking Operations.
3. Enclosure: 18-gauge Type 304 stainless steel, fully welded, 63 in. long by model width; 1.5-in. perimeter flange at each end for welded duct connection; full-width sloped top panel; two full-width T304 stainless bottom channels, 1.5 x 4 in.
4. Access: three removable, gasketed 18-gauge stainless access doors on the service side (doors both sides optional).
5. Filtration, in airflow order: F1 MERV 9 multi-pocket pre-filters; F2 MERV 14 multi-pocket high-efficiency filters; F3 MERV 14 multi-pocket high-efficiency filters, or carbon filters where odor treatment is required.
6. Fire protection: factory fire-suppression pre-piping to nozzles, for connection by the fire-protection installer to an ANSUL or other customer-selected system (mechanical fusible-link detectors). A building sprinkler connection is not provided.
7. Drains: three 1-1/2 in. stainless FPT cleaning drain couplings.
8. Monitoring: static pressure controls enclosure with gauge, fan-on and adjustable high static pressure switches, 120/24 VAC transformer; wall-mounted stainless status panel (green: exhaust on; blinking red: service required).
9. Electrical: 120 VAC supply to the unit (by others); 3-wire 18-gauge plenum cable from unit to status panel (by others).
10. Clearances: 30 in. on the service side; 18 in. to combustibles and building insulation on other sides, or zero to noncombustible materials.
11. Exhaust fan (by others): UL Listed for kitchen exhaust, backward-inclined utility type with adjustable RPM. Initial PCU resistance 1.54 in. w.g.; size the fan for 2.5 in. w.g. plus hood and duct static losses.

Listing details: equipment listings. For drawings or project questions, contact Molitron.