FPS-1650, FPS-3250, and FPS-5000 Site and Utility Requirements – South-Tek Systems

Applies to: South-Tek Systems N2-BLAST® FPS-1650, FPS-3250, and FPS-5000 fire protection nitrogen generators.

Confirm these site and utility requirements before the unit ships or the riser room is roughed in. All three models share the same floor-standing cabinet, but site preparation splits along one line: the FPS-1650 has an internal oil-free compressor and needs nothing but power and piping, while the FPS-3250 and FPS-5000 are fed by an external air compressor that the site has to accommodate, power, and pipe. Getting these conditions right up front is what keeps the system reaching and holding 98.5% purity, and it prevents the startup problems that are expensive to fix after the walls close in.

Requirements at a glance

Requirement	FPS-1650	FPS-3250 & FPS-5000
Environment	Indoor, nonhazardous, well-ventilated, dry; 40–100°F (4–38°C)
Electrical	120–240 VAC, 50/60 Hz, 1-ph; draws < 8 A	120–240 VAC, 50/60 Hz, 1-ph; draws < 5 A (plus separate service for the feed compressor and dryer)
Over-current protection	Built-in 20 A power entry module; UL 508A ICP control panel
Air supply	Internal 2 HP oil-free compressor with its own intake pre-filter — no external feed air	External compressor required: 100–125 PSIG, 40–100°F, dew point below 40°F
Air drying	Not required	Refrigerated drying required to hold dew point below 40°F — integral or separate depending on configuration
Cabinet connections	1/2" NPT female (air inlet and N2 out) unless otherwise stated
Drains	Two 1/4" filter drain connections low on the left side of the cabinet, piped individually to a floor sink and left open to atmosphere
Clearance	36" at the front; 6" minimum on all sides for ventilation, with about 36" at the left side where practical for touchscreen and drain access; top clear for gas-line connections
Cabinet size	26" W x 18" D x 59" H (about 63.6" overall to the top gas fitting)
Floor	Hard, flat, level, rated 300+ lb (unit ~223 lb)	Hard, flat, level; unit ~243 lb (FPS-3250) / ~303 lb (FPS-5000), plus the feed compressor and any receiver — rate the floor with margin above those weights
Noise	< 90 dBA — plan for hearing protection in the room while the equipment runs

Installation environment

Install the generator indoors in a nonhazardous, climate-controlled location that is well ventilated and never sealed off from normal air changes. Hold the ambient temperature between 40°F and 100°F (4–38°C) and keep the area dry. Where practical, put the generator and its supporting equipment in the same room — it shortens the air piping, reduces pressure drop, and keeps service and troubleshooting in one place.

⚠ Warning Nitrogen is colorless, odorless, and non-toxic, but it displaces oxygen. Never install the equipment in a sealed closet or an unventilated confined space, and vent any relief or exhaust to a well-ventilated area or outdoors.

Footprint, floor, and clearance

All three models use the same floor-standing cabinet: 26" wide, 18" deep, and 59" tall, rising to roughly 63.6" with the gas fitting on top. Weight is approximately 223 lb (FPS-1650), 243 lb (FPS-3250), and 303 lb (FPS-5000). The O&M calls for a hard, flat surface rated for 300+ lb; on the FPS-5000 that is barely above the unit's own weight, so rate the floor with margin. Four anchor bolt-holes are provided in the support legs; anchoring is not required by South-Tek, but follow site and local code for securing equipment.

Provide 36" of clearance at the front — routine maintenance and the filter change are done through the front door, and NEC Article 110.26 calls for 36" of working space in front of the electrical panel.
Provide 6" minimum on all sides for ventilation. On the left side, allow closer to 36" where the room permits — the touchscreen controller and both filter drain connections are on that side, so it should not be pushed tight against a wall.
Leave the top of the cabinet clear for the gas-line connections and the storage-tank pressure gauge.

Delivery and access

The generator arrives bolted into a wooden crate and has to be unbolted, lifted out, and moved on a floor jack. Walk the route from the dock to the riser room before the delivery date and confirm door widths, turns, thresholds, and elevator capacity for a 59"-tall cabinet weighing up to about 303 lb.

If the unit lands on site before the room is ready, store it upright (or in its crate as shipped) in a dry, climate-controlled space held between 60°F and 80°F — a narrower window than the 40–100°F operating range. Never stack anything on top of it, and keep gas lines capped and dry so moisture does not enter the generator at hook-up. Unpacking, shipping-bolt removal, and mounting are covered in Installation and Startup.

Cabinet connections and layout

Every N2-BLAST FPS model ships with 1/2" NPT female connections unless the order specified otherwise. Confirm each connection location against the general arrangement drawing in your installation package before opening a valve or energizing the unit. The drawing below shows the cabinet dimensions and the numbered external components.

#	Component	Service
1	1/2" FNPT ball valve	Air inlet
2	1/2" FNPT ball valve	N2 out
3	0–160 PSIG pressure gauge	Internal storage tank pressure
4	1/4" coupling (two places)	Filter drain line connections
5	Electrical assembly	System controller (PLC) and touchscreen
6	Power entry module, 20 A	System main power connection
7	UL 508A open industrial panel	Electrical connections
8	UL 508A open industrial control panel certification label	—
9	Electrical panel and terminal block torque specification label	—
10	Product serial number label	—
11	Buzzer and display screen warning information label	—
12	Nitrogen generator information label	—

Electrical requirements

Supply 120–240 VAC, 50/60 Hz, single phase. The FPS-1650 draws less than 8 A; the FPS-3250 and FPS-5000 draw less than 5 A.
Land the incoming power at the cabinet's 20 A power entry module — not directly onto the internal power supply. The unit's own over-current protection is built into that module.
Either a hard-wired connection or a dedicated 20 A outlet is acceptable. Which one your unit is built for varies by order — the O&M describes a standard 3-prong cord unless otherwise specified, and many fire-protection installs are hard-wired. Confirm the configuration before rough-in so the branch circuit and disconnect match.
The control panel carries UL 508A ICP certification. Electrical schematics are available from South-Tek on request.
FPS-3250 and FPS-5000 only: the external air compressor and dryer need their own service, sized and protected per their nameplates. If the compressor is three-phase, verify rotation before first start — running a compressor backwards will damage it and it is one of the most common startup call-backs.

Air supply

FPS-1650. No site air is required. The FPS-1650 has an integrated 2 HP oil-free compressor with its own intake pre-filter, so the only utilities to plan for are power, the nitrogen line, and drains.

FPS-3250 and FPS-5000. These models are fed by an external air compressor, normally a South-Tek-supplied C-Aire unit sized to the system. Refrigerated drying is part of the package on these models — whether it is integral to the generator or a separate dryer in the room depends on how the system was configured, so confirm which applies before laying out the space. The feed air has to meet all of the following at the generator inlet:

Pressure: 100 PSIG minimum, 125 PSIG maximum, unless the unit was configured otherwise. Set the incoming air to the design air-in pressure so the unit meets its purity and flow specification.
Temperature: 40–100°F (4–38°C).
Dew point: below 40°F (4°C). This is what the refrigerated drying is there for — moisture carried into the PSA beds ruins the carbon molecular sieve, and that damage is not a warranty repair.
Flow: peak feed-air demand can reach up to three times the specified average feed-air flow rate. Size the compressor, receiver, and piping for the peak, not the average.

⚠ Warning Set the cabinet air-inlet regulator to 120–125 PSIG static (no flow). 150 PSIG is the absolute maximum — feeding the generator above that voids the warranty. Air that does not meet the temperature, dew point, and pressure requirements above can cause damage that is not covered under warranty.

Size the feed compressor by the largest single zone the system supervises, not by horsepower and not by the sum of all zones. NFPA 13 requires that zone to reach 40 PSI within 30 minutes, and that is the number the compressor selection has to satisfy. South-Tek matches a C-Aire feed compressor to the system for these models; have South-Tek confirm the selection against the actual zone gallonage and supervisory pressure before it is ordered. The generator carries a 14.8-gallon internal nitrogen storage tank — an additional receiver belongs in the room only if the design needs storage beyond that.

Drain connections

Both filters drain automatically, and those drains have to go somewhere. The cabinet has two 1/4" drain connections low on the left side, each labelled Drain line — do not plug. Plumb them individually to the nearest floor sink or site drain and leave them open to atmosphere. Do not tee them together, and do not cap them.

ℹ Note The O&M gives the drain fitting as 1/4" OD on the FPS-1650 and 1/4" NPT on the FPS-3250 and FPS-5000 — but the FPS-3250 dimensional drawing in the same manual shows a 1/4" OD push-to-connect coupling. Check the actual ports, or the general arrangement drawing in your installation package, before buying fittings. On the FPS-3250 and FPS-5000 the third (absorbing) filter has no auto-drain and needs no drain line.

Planning the riser room

The generator is one piece of a larger assembly. Plan space, power, and piping for everything that has to live in the room:

Feed compressor (FPS-3250 / FPS-5000). Allow 18" minimum clearance on all sides, and keep its tank drain accessible.
Separate dryer or receiver, if the design includes one. A refrigerated dryer that is not integral to the generator, or a receiver beyond the generator's 14.8-gallon onboard tank, needs its own floor space, power, and drain. Confirm from the submittal whether either is part of your package.
Bypass piping. Install it on every job — it is what lets the system stay supervised while the generator is serviced.
Air Maintenance Device (AMD), one per riser. Regulator only, no pressure switch. It has to close fully on a trip so the trip valve sees full differential.
AutoPurge System (APS), one per riser. Mount horizontally at a remote, accessible point where water will not collect.
Purity sample lines. Run a sample line from each zone back to the Quick Check™ PowerSaver Manifold.
Floor sink or site drain within reach of the generator, compressor, and dryer drain lines.

Additional piping and hosing

Any piping or hosing supplied by others must meet the unit's flow, pressure, and temperature requirements. If the run from the air receiver to the generator exceeds 50 feet, have a piping contractor size the line — an undersized long run shows up later as low feed pressure and a generator that never reaches standby. Route piping so service access stays clear and pressure drop stays low, and use Teflon tape or an equivalent sealant on all threaded fittings.

What the installing contractor provides

A hard, flat, level pad or floor area rated for the equipment weight.
Hard-wired 120–240 V single-phase service to the generator, plus separate service to the feed compressor and dryer on the FPS-3250 and FPS-5000.
Compressed-air piping between the feed compressor and the generator, sized for the run (FPS-3250 and FPS-5000).
Bypass piping around the generator.
One AMD per riser.
Sample lines from each zone to the Quick Check™ PowerSaver Manifold.
Drain lines from the generator and from any compressor or dryer to a floor sink.

Codes the AHJ will ask about

Verify section numbers against the edition adopted by your local authority having jurisdiction before citing them in writing — numbering shifts between editions.

NFPA 13, 7.2.6 — the air supply must bring the system to 40 PSI within 30 minutes. This drives feed-compressor sizing.
NFPA 13, 7.2.6.2.1 — an air maintenance device is required.
NFPA 13, 8.16 — drainage and air supply provisions.
NFPA 13, Annex E — nitrogen is an accepted corrosion-mitigation supervisory gas.
NFPA 70 (NEC), Article 110.26 — 36" working clearance in front of the electrical panel. Articles 430 and 440 apply to the feed compressor's motor circuit.
NFPA 55 — applies if bottled nitrogen backup is used on site (storage limits, ventilation, signage). On-site PSA generation is generally exempt, but verify with the AHJ.
FM Global Data Sheets 2-0 and 2-1, and FM Approval Standard 1035 — South-Tek is FM Approved to Standard 1035.

Before installation — site checklist

Verify the exact model on the nameplate, and confirm whether it is an FPS-1650 (internal compressor) or an FPS-3250 / FPS-5000 (external air required).
Confirm the room holds 40–100°F, is well ventilated, and is not a sealed space.
Confirm the floor supports the unit's weight with margin and that the 26" x 18" footprint fits with 36" front clearance and at least 6" on the sides.
Walk the delivery route — door widths, turns, and elevator capacity for a 59" cabinet up to ~303 lb — and confirm 60–80°F storage if the unit arrives before the room is ready.
Confirm the electrical service matches the unit's configuration and lands at the power entry module.
Confirm the feed compressor and dryer are sized, ordered, and scheduled (FPS-3250 and FPS-5000), and that dew point below 40°F can be met at the generator inlet.
Confirm the floor sink or site drain location, and plan both drain runs.
Confirm bypass piping, AMD, and APS locations are on the drawings.
Review the general arrangement drawing in the installation package against the actual room before rough-in.

Manual download

FPS-1650, FPS-3250, and FPS-5000 O&M Manual

Need help? South-Tek Systems Service — Phone: (910) 415-1880 · Open a support ticket at support@southteksystems911.zendesk.com or through the Help Center.